diff --git a/cmd/cmd.go b/cmd/cmd.go
index 8d9d1ee07..bb7ab8f9b 100644
--- a/cmd/cmd.go
+++ b/cmd/cmd.go
@@ -15,7 +15,7 @@ import (
 	"strings"
 	"syscall"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
 
@@ -65,7 +65,7 @@ func initDBDisableConsole(disableConsole bool) error {
 	setting.InitDBConfig()
 
 	setting.NewXORMLogService(disableConsole)
-	if err := models.SetEngine(); err != nil {
+	if err := db.SetEngine(); err != nil {
 		return fmt.Errorf("models.SetEngine: %v", err)
 	}
 	return nil
diff --git a/cmd/convert.go b/cmd/convert.go
index aa404d64f..20e4045c3 100644
--- a/cmd/convert.go
+++ b/cmd/convert.go
@@ -7,7 +7,7 @@ package cmd
 import (
 	"fmt"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 
@@ -39,7 +39,7 @@ func runConvert(ctx *cli.Context) error {
 		return nil
 	}
 
-	if err := models.ConvertUtf8ToUtf8mb4(); err != nil {
+	if err := db.ConvertUtf8ToUtf8mb4(); err != nil {
 		log.Fatal("Failed to convert database from utf8 to utf8mb4: %v", err)
 		return err
 	}
diff --git a/cmd/doctor.go b/cmd/doctor.go
index 2e7927543..31708e990 100644
--- a/cmd/doctor.go
+++ b/cmd/doctor.go
@@ -12,7 +12,7 @@ import (
 	"strings"
 	"text/tabwriter"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/models/migrations"
 	"code.gitea.io/gitea/modules/doctor"
 	"code.gitea.io/gitea/modules/log"
@@ -96,7 +96,7 @@ func runRecreateTable(ctx *cli.Context) error {
 	setting.Cfg.Section("log").Key("XORM").SetValue(",")
 
 	setting.NewXORMLogService(!ctx.Bool("debug"))
-	if err := models.SetEngine(); err != nil {
+	if err := db.SetEngine(); err != nil {
 		fmt.Println(err)
 		fmt.Println("Check if you are using the right config file. You can use a --config directive to specify one.")
 		return nil
@@ -108,13 +108,13 @@ func runRecreateTable(ctx *cli.Context) error {
 		names = append(names, args.Get(i))
 	}
 
-	beans, err := models.NamesToBean(names...)
+	beans, err := db.NamesToBean(names...)
 	if err != nil {
 		return err
 	}
 	recreateTables := migrations.RecreateTables(beans...)
 
-	return models.NewEngine(context.Background(), func(x *xorm.Engine) error {
+	return db.NewEngine(context.Background(), func(x *xorm.Engine) error {
 		if err := migrations.EnsureUpToDate(x); err != nil {
 			return err
 		}
diff --git a/cmd/dump.go b/cmd/dump.go
index 9ce7c2636..5be77d634 100644
--- a/cmd/dump.go
+++ b/cmd/dump.go
@@ -14,7 +14,7 @@ import (
 	"strings"
 	"time"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/json"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -174,7 +174,7 @@ func runDump(ctx *cli.Context) error {
 	}
 	setting.NewServices() // cannot access session settings otherwise
 
-	err := models.SetEngine()
+	err := db.SetEngine()
 	if err != nil {
 		return err
 	}
@@ -264,7 +264,7 @@ func runDump(ctx *cli.Context) error {
 		log.Info("Dumping database...")
 	}
 
-	if err := models.DumpDatabase(dbDump.Name(), targetDBType); err != nil {
+	if err := db.DumpDatabase(dbDump.Name(), targetDBType); err != nil {
 		fatal("Failed to dump database: %v", err)
 	}
 
diff --git a/cmd/migrate.go b/cmd/migrate.go
index afed07f53..a5dfed20b 100644
--- a/cmd/migrate.go
+++ b/cmd/migrate.go
@@ -7,7 +7,7 @@ package cmd
 import (
 	"context"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/models/migrations"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -35,7 +35,7 @@ func runMigrate(ctx *cli.Context) error {
 	log.Info("Configuration file: %s", setting.CustomConf)
 	setting.InitDBConfig()
 
-	if err := models.NewEngine(context.Background(), migrations.Migrate); err != nil {
+	if err := db.NewEngine(context.Background(), migrations.Migrate); err != nil {
 		log.Fatal("Failed to initialize ORM engine: %v", err)
 		return err
 	}
diff --git a/cmd/migrate_storage.go b/cmd/migrate_storage.go
index 08524953b..d9ca8a083 100644
--- a/cmd/migrate_storage.go
+++ b/cmd/migrate_storage.go
@@ -10,6 +10,7 @@ import (
 	"strings"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/models/migrations"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -117,7 +118,7 @@ func runMigrateStorage(ctx *cli.Context) error {
 	log.Info("Configuration file: %s", setting.CustomConf)
 	setting.InitDBConfig()
 
-	if err := models.NewEngine(context.Background(), migrations.Migrate); err != nil {
+	if err := db.NewEngine(context.Background(), migrations.Migrate); err != nil {
 		log.Fatal("Failed to initialize ORM engine: %v", err)
 		return err
 	}
diff --git a/contrib/fixtures/fixture_generation.go b/contrib/fixtures/fixture_generation.go
index 802a2ca30..1665dab64 100644
--- a/contrib/fixtures/fixture_generation.go
+++ b/contrib/fixtures/fixture_generation.go
@@ -11,6 +11,7 @@ import (
 	"path/filepath"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 // To generate derivative fixtures, execute the following from Gitea's repository base dir:
@@ -31,11 +32,11 @@ var (
 func main() {
 	pathToGiteaRoot := "."
 	fixturesDir = filepath.Join(pathToGiteaRoot, "models", "fixtures")
-	if err := models.CreateTestEngine(fixturesDir); err != nil {
+	if err := db.CreateTestEngine(fixturesDir); err != nil {
 		fmt.Printf("CreateTestEngine: %+v", err)
 		os.Exit(1)
 	}
-	if err := models.PrepareTestDatabase(); err != nil {
+	if err := db.PrepareTestDatabase(); err != nil {
 		fmt.Printf("PrepareTestDatabase: %+v\n", err)
 		os.Exit(1)
 	}
diff --git a/contrib/pr/checkout.go b/contrib/pr/checkout.go
index 902c9ea62..44c3fd517 100644
--- a/contrib/pr/checkout.go
+++ b/contrib/pr/checkout.go
@@ -26,6 +26,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	gitea_git "code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/markup"
 	"code.gitea.io/gitea/modules/markup/external"
@@ -87,27 +88,27 @@ func runPR() {
 		setting.Database.Path = ":memory:"
 		setting.Database.Timeout = 500
 	*/
-	db := setting.Cfg.Section("database")
-	db.NewKey("DB_TYPE", "sqlite3")
-	db.NewKey("PATH", ":memory:")
+	dbCfg := setting.Cfg.Section("database")
+	dbCfg.NewKey("DB_TYPE", "sqlite3")
+	dbCfg.NewKey("PATH", ":memory:")
 
 	routers.NewServices()
 	setting.Database.LogSQL = true
 	//x, err = xorm.NewEngine("sqlite3", "file::memory:?cache=shared")
 
-	models.NewEngine(context.Background(), func(_ *xorm.Engine) error {
+	db.NewEngine(context.Background(), func(_ *xorm.Engine) error {
 		return nil
 	})
-	models.HasEngine = true
+	db.HasEngine = true
 	//x.ShowSQL(true)
-	err = models.InitFixtures(
+	err = db.InitFixtures(
 		path.Join(curDir, "models/fixtures/"),
 	)
 	if err != nil {
 		fmt.Printf("Error initializing test database: %v\n", err)
 		os.Exit(1)
 	}
-	models.LoadFixtures()
+	db.LoadFixtures()
 	util.RemoveAll(setting.RepoRootPath)
 	util.RemoveAll(models.LocalCopyPath())
 	util.CopyDir(path.Join(curDir, "integrations/gitea-repositories-meta"), setting.RepoRootPath)
diff --git a/integrations/admin_user_test.go b/integrations/admin_user_test.go
index 96233436e..3acf34904 100644
--- a/integrations/admin_user_test.go
+++ b/integrations/admin_user_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 
 	"github.com/stretchr/testify/assert"
 )
@@ -60,7 +61,7 @@ func makeRequest(t *testing.T, formData models.User, headerCode int) {
 	})
 
 	session.MakeRequest(t, req, headerCode)
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: formData.ID}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: formData.ID}).(*models.User)
 	assert.Equal(t, formData.Name, user.Name)
 	assert.Equal(t, formData.LoginName, user.LoginName)
 	assert.Equal(t, formData.Email, user.Email)
diff --git a/integrations/api_admin_org_test.go b/integrations/api_admin_org_test.go
index b10f5607d..7b149a38d 100644
--- a/integrations/api_admin_org_test.go
+++ b/integrations/api_admin_org_test.go
@@ -11,6 +11,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -42,7 +43,7 @@ func TestAPIAdminOrgCreate(t *testing.T) {
 		assert.Equal(t, org.Location, apiOrg.Location)
 		assert.Equal(t, org.Visibility, apiOrg.Visibility)
 
-		models.AssertExistsAndLoadBean(t, &models.User{
+		db.AssertExistsAndLoadBean(t, &models.User{
 			Name:      org.UserName,
 			LowerName: strings.ToLower(org.UserName),
 			FullName:  org.FullName,
diff --git a/integrations/api_admin_test.go b/integrations/api_admin_test.go
index da6a89c97..ae3cc7dcf 100644
--- a/integrations/api_admin_test.go
+++ b/integrations/api_admin_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/json"
 	api "code.gitea.io/gitea/modules/structs"
 
@@ -20,7 +21,7 @@ func TestAPIAdminCreateAndDeleteSSHKey(t *testing.T) {
 	defer prepareTestEnv(t)()
 	// user1 is an admin user
 	session := loginUser(t, "user1")
-	keyOwner := models.AssertExistsAndLoadBean(t, &models.User{Name: "user2"}).(*models.User)
+	keyOwner := db.AssertExistsAndLoadBean(t, &models.User{Name: "user2"}).(*models.User)
 
 	token := getTokenForLoggedInUser(t, session)
 	urlStr := fmt.Sprintf("/api/v1/admin/users/%s/keys?token=%s", keyOwner.Name, token)
@@ -32,7 +33,7 @@ func TestAPIAdminCreateAndDeleteSSHKey(t *testing.T) {
 
 	var newPublicKey api.PublicKey
 	DecodeJSON(t, resp, &newPublicKey)
-	models.AssertExistsAndLoadBean(t, &models.PublicKey{
+	db.AssertExistsAndLoadBean(t, &models.PublicKey{
 		ID:          newPublicKey.ID,
 		Name:        newPublicKey.Title,
 		Content:     newPublicKey.Key,
@@ -43,7 +44,7 @@ func TestAPIAdminCreateAndDeleteSSHKey(t *testing.T) {
 	req = NewRequestf(t, "DELETE", "/api/v1/admin/users/%s/keys/%d?token=%s",
 		keyOwner.Name, newPublicKey.ID, token)
 	session.MakeRequest(t, req, http.StatusNoContent)
-	models.AssertNotExistsBean(t, &models.PublicKey{ID: newPublicKey.ID})
+	db.AssertNotExistsBean(t, &models.PublicKey{ID: newPublicKey.ID})
 }
 
 func TestAPIAdminDeleteMissingSSHKey(t *testing.T) {
@@ -52,7 +53,7 @@ func TestAPIAdminDeleteMissingSSHKey(t *testing.T) {
 	session := loginUser(t, "user1")
 
 	token := getTokenForLoggedInUser(t, session)
-	req := NewRequestf(t, "DELETE", "/api/v1/admin/users/user1/keys/%d?token=%s", models.NonexistentID, token)
+	req := NewRequestf(t, "DELETE", "/api/v1/admin/users/user1/keys/%d?token=%s", db.NonexistentID, token)
 	session.MakeRequest(t, req, http.StatusNotFound)
 }
 
@@ -127,7 +128,7 @@ func TestAPIListUsers(t *testing.T) {
 		}
 	}
 	assert.True(t, found)
-	numberOfUsers := models.GetCount(t, &models.User{}, "type = 0")
+	numberOfUsers := db.GetCount(t, &models.User{}, "type = 0")
 	assert.Equal(t, numberOfUsers, len(users))
 }
 
@@ -193,7 +194,7 @@ func TestAPIEditUser(t *testing.T) {
 	json.Unmarshal(resp.Body.Bytes(), &errMap)
 	assert.EqualValues(t, "email is not allowed to be empty string", errMap["message"].(string))
 
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{LoginName: "user2"}).(*models.User)
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{LoginName: "user2"}).(*models.User)
 	assert.False(t, user2.IsRestricted)
 	bTrue := true
 	req = NewRequestWithJSON(t, "PATCH", urlStr, api.EditUserOption{
@@ -204,6 +205,6 @@ func TestAPIEditUser(t *testing.T) {
 		Restricted: &bTrue,
 	})
 	session.MakeRequest(t, req, http.StatusOK)
-	user2 = models.AssertExistsAndLoadBean(t, &models.User{LoginName: "user2"}).(*models.User)
+	user2 = db.AssertExistsAndLoadBean(t, &models.User{LoginName: "user2"}).(*models.User)
 	assert.True(t, user2.IsRestricted)
 }
diff --git a/integrations/api_comment_test.go b/integrations/api_comment_test.go
index f64f4a1c9..a5513af6e 100644
--- a/integrations/api_comment_test.go
+++ b/integrations/api_comment_test.go
@@ -11,6 +11,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/convert"
 	api "code.gitea.io/gitea/modules/structs"
 
@@ -20,11 +21,11 @@ import (
 func TestAPIListRepoComments(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	comment := models.AssertExistsAndLoadBean(t, &models.Comment{},
-		models.Cond("type = ?", models.CommentTypeComment)).(*models.Comment)
-	issue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: comment.IssueID}).(*models.Issue)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: issue.RepoID}).(*models.Repository)
-	repoOwner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	comment := db.AssertExistsAndLoadBean(t, &models.Comment{},
+		db.Cond("type = ?", models.CommentTypeComment)).(*models.Comment)
+	issue := db.AssertExistsAndLoadBean(t, &models.Issue{ID: comment.IssueID}).(*models.Issue)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: issue.RepoID}).(*models.Repository)
+	repoOwner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, repoOwner.Name)
 	link, _ := url.Parse(fmt.Sprintf("/api/v1/repos/%s/%s/issues/comments", repoOwner.Name, repo.Name))
@@ -36,9 +37,9 @@ func TestAPIListRepoComments(t *testing.T) {
 	assert.Len(t, apiComments, 2)
 	for _, apiComment := range apiComments {
 		c := &models.Comment{ID: apiComment.ID}
-		models.AssertExistsAndLoadBean(t, c,
-			models.Cond("type = ?", models.CommentTypeComment))
-		models.AssertExistsAndLoadBean(t, &models.Issue{ID: c.IssueID, RepoID: repo.ID})
+		db.AssertExistsAndLoadBean(t, c,
+			db.Cond("type = ?", models.CommentTypeComment))
+		db.AssertExistsAndLoadBean(t, &models.Issue{ID: c.IssueID, RepoID: repo.ID})
 	}
 
 	//test before and since filters
@@ -66,11 +67,11 @@ func TestAPIListRepoComments(t *testing.T) {
 func TestAPIListIssueComments(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	comment := models.AssertExistsAndLoadBean(t, &models.Comment{},
-		models.Cond("type = ?", models.CommentTypeComment)).(*models.Comment)
-	issue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: comment.IssueID}).(*models.Issue)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: issue.RepoID}).(*models.Repository)
-	repoOwner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	comment := db.AssertExistsAndLoadBean(t, &models.Comment{},
+		db.Cond("type = ?", models.CommentTypeComment)).(*models.Comment)
+	issue := db.AssertExistsAndLoadBean(t, &models.Issue{ID: comment.IssueID}).(*models.Issue)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: issue.RepoID}).(*models.Repository)
+	repoOwner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, repoOwner.Name)
 	req := NewRequestf(t, "GET", "/api/v1/repos/%s/%s/issues/%d/comments",
@@ -79,8 +80,8 @@ func TestAPIListIssueComments(t *testing.T) {
 
 	var comments []*api.Comment
 	DecodeJSON(t, resp, &comments)
-	expectedCount := models.GetCount(t, &models.Comment{IssueID: issue.ID},
-		models.Cond("type = ?", models.CommentTypeComment))
+	expectedCount := db.GetCount(t, &models.Comment{IssueID: issue.ID},
+		db.Cond("type = ?", models.CommentTypeComment))
 	assert.EqualValues(t, expectedCount, len(comments))
 }
 
@@ -88,9 +89,9 @@ func TestAPICreateComment(t *testing.T) {
 	defer prepareTestEnv(t)()
 	const commentBody = "Comment body"
 
-	issue := models.AssertExistsAndLoadBean(t, &models.Issue{}).(*models.Issue)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: issue.RepoID}).(*models.Repository)
-	repoOwner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	issue := db.AssertExistsAndLoadBean(t, &models.Issue{}).(*models.Issue)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: issue.RepoID}).(*models.Repository)
+	repoOwner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, repoOwner.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -104,16 +105,16 @@ func TestAPICreateComment(t *testing.T) {
 	var updatedComment api.Comment
 	DecodeJSON(t, resp, &updatedComment)
 	assert.EqualValues(t, commentBody, updatedComment.Body)
-	models.AssertExistsAndLoadBean(t, &models.Comment{ID: updatedComment.ID, IssueID: issue.ID, Content: commentBody})
+	db.AssertExistsAndLoadBean(t, &models.Comment{ID: updatedComment.ID, IssueID: issue.ID, Content: commentBody})
 }
 
 func TestAPIGetComment(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	comment := models.AssertExistsAndLoadBean(t, &models.Comment{ID: 2}).(*models.Comment)
+	comment := db.AssertExistsAndLoadBean(t, &models.Comment{ID: 2}).(*models.Comment)
 	assert.NoError(t, comment.LoadIssue())
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: comment.Issue.RepoID}).(*models.Repository)
-	repoOwner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: comment.Issue.RepoID}).(*models.Repository)
+	repoOwner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, repoOwner.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -138,11 +139,11 @@ func TestAPIEditComment(t *testing.T) {
 	defer prepareTestEnv(t)()
 	const newCommentBody = "This is the new comment body"
 
-	comment := models.AssertExistsAndLoadBean(t, &models.Comment{},
-		models.Cond("type = ?", models.CommentTypeComment)).(*models.Comment)
-	issue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: comment.IssueID}).(*models.Issue)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: issue.RepoID}).(*models.Repository)
-	repoOwner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	comment := db.AssertExistsAndLoadBean(t, &models.Comment{},
+		db.Cond("type = ?", models.CommentTypeComment)).(*models.Comment)
+	issue := db.AssertExistsAndLoadBean(t, &models.Issue{ID: comment.IssueID}).(*models.Issue)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: issue.RepoID}).(*models.Repository)
+	repoOwner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, repoOwner.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -157,17 +158,17 @@ func TestAPIEditComment(t *testing.T) {
 	DecodeJSON(t, resp, &updatedComment)
 	assert.EqualValues(t, comment.ID, updatedComment.ID)
 	assert.EqualValues(t, newCommentBody, updatedComment.Body)
-	models.AssertExistsAndLoadBean(t, &models.Comment{ID: comment.ID, IssueID: issue.ID, Content: newCommentBody})
+	db.AssertExistsAndLoadBean(t, &models.Comment{ID: comment.ID, IssueID: issue.ID, Content: newCommentBody})
 }
 
 func TestAPIDeleteComment(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	comment := models.AssertExistsAndLoadBean(t, &models.Comment{},
-		models.Cond("type = ?", models.CommentTypeComment)).(*models.Comment)
-	issue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: comment.IssueID}).(*models.Issue)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: issue.RepoID}).(*models.Repository)
-	repoOwner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	comment := db.AssertExistsAndLoadBean(t, &models.Comment{},
+		db.Cond("type = ?", models.CommentTypeComment)).(*models.Comment)
+	issue := db.AssertExistsAndLoadBean(t, &models.Issue{ID: comment.IssueID}).(*models.Issue)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: issue.RepoID}).(*models.Repository)
+	repoOwner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, repoOwner.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -175,5 +176,5 @@ func TestAPIDeleteComment(t *testing.T) {
 		repoOwner.Name, repo.Name, comment.ID, token)
 	session.MakeRequest(t, req, http.StatusNoContent)
 
-	models.AssertNotExistsBean(t, &models.Comment{ID: comment.ID})
+	db.AssertNotExistsBean(t, &models.Comment{ID: comment.ID})
 }
diff --git a/integrations/api_issue_label_test.go b/integrations/api_issue_label_test.go
index 64c3515dd..4508069e1 100644
--- a/integrations/api_issue_label_test.go
+++ b/integrations/api_issue_label_test.go
@@ -11,16 +11,17 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestAPIModifyLabels(t *testing.T) {
-	assert.NoError(t, models.LoadFixtures())
+	assert.NoError(t, db.LoadFixtures())
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 2}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 2}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 	session := loginUser(t, owner.Name)
 	token := getTokenForLoggedInUser(t, session)
 	urlStr := fmt.Sprintf("/api/v1/repos/%s/%s/labels?token=%s", owner.Name, repo.Name, token)
@@ -34,7 +35,7 @@ func TestAPIModifyLabels(t *testing.T) {
 	resp := session.MakeRequest(t, req, http.StatusCreated)
 	apiLabel := new(api.Label)
 	DecodeJSON(t, resp, &apiLabel)
-	dbLabel := models.AssertExistsAndLoadBean(t, &models.Label{ID: apiLabel.ID, RepoID: repo.ID}).(*models.Label)
+	dbLabel := db.AssertExistsAndLoadBean(t, &models.Label{ID: apiLabel.ID, RepoID: repo.ID}).(*models.Label)
 	assert.EqualValues(t, dbLabel.Name, apiLabel.Name)
 	assert.EqualValues(t, strings.TrimLeft(dbLabel.Color, "#"), apiLabel.Color)
 
@@ -87,12 +88,12 @@ func TestAPIModifyLabels(t *testing.T) {
 }
 
 func TestAPIAddIssueLabels(t *testing.T) {
-	assert.NoError(t, models.LoadFixtures())
+	assert.NoError(t, db.LoadFixtures())
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	issue := models.AssertExistsAndLoadBean(t, &models.Issue{RepoID: repo.ID}).(*models.Issue)
-	_ = models.AssertExistsAndLoadBean(t, &models.Label{RepoID: repo.ID, ID: 2}).(*models.Label)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	issue := db.AssertExistsAndLoadBean(t, &models.Issue{RepoID: repo.ID}).(*models.Issue)
+	_ = db.AssertExistsAndLoadBean(t, &models.Label{RepoID: repo.ID, ID: 2}).(*models.Label)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, owner.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -104,18 +105,18 @@ func TestAPIAddIssueLabels(t *testing.T) {
 	resp := session.MakeRequest(t, req, http.StatusOK)
 	var apiLabels []*api.Label
 	DecodeJSON(t, resp, &apiLabels)
-	assert.Len(t, apiLabels, models.GetCount(t, &models.IssueLabel{IssueID: issue.ID}))
+	assert.Len(t, apiLabels, db.GetCount(t, &models.IssueLabel{IssueID: issue.ID}))
 
-	models.AssertExistsAndLoadBean(t, &models.IssueLabel{IssueID: issue.ID, LabelID: 2})
+	db.AssertExistsAndLoadBean(t, &models.IssueLabel{IssueID: issue.ID, LabelID: 2})
 }
 
 func TestAPIReplaceIssueLabels(t *testing.T) {
-	assert.NoError(t, models.LoadFixtures())
+	assert.NoError(t, db.LoadFixtures())
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	issue := models.AssertExistsAndLoadBean(t, &models.Issue{RepoID: repo.ID}).(*models.Issue)
-	label := models.AssertExistsAndLoadBean(t, &models.Label{RepoID: repo.ID}).(*models.Label)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	issue := db.AssertExistsAndLoadBean(t, &models.Issue{RepoID: repo.ID}).(*models.Issue)
+	label := db.AssertExistsAndLoadBean(t, &models.Label{RepoID: repo.ID}).(*models.Label)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, owner.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -131,15 +132,15 @@ func TestAPIReplaceIssueLabels(t *testing.T) {
 		assert.EqualValues(t, label.ID, apiLabels[0].ID)
 	}
 
-	models.AssertCount(t, &models.IssueLabel{IssueID: issue.ID}, 1)
-	models.AssertExistsAndLoadBean(t, &models.IssueLabel{IssueID: issue.ID, LabelID: label.ID})
+	db.AssertCount(t, &models.IssueLabel{IssueID: issue.ID}, 1)
+	db.AssertExistsAndLoadBean(t, &models.IssueLabel{IssueID: issue.ID, LabelID: label.ID})
 }
 
 func TestAPIModifyOrgLabels(t *testing.T) {
-	assert.NoError(t, models.LoadFixtures())
+	assert.NoError(t, db.LoadFixtures())
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 	user := "user1"
 	session := loginUser(t, user)
 	token := getTokenForLoggedInUser(t, session)
@@ -154,7 +155,7 @@ func TestAPIModifyOrgLabels(t *testing.T) {
 	resp := session.MakeRequest(t, req, http.StatusCreated)
 	apiLabel := new(api.Label)
 	DecodeJSON(t, resp, &apiLabel)
-	dbLabel := models.AssertExistsAndLoadBean(t, &models.Label{ID: apiLabel.ID, OrgID: owner.ID}).(*models.Label)
+	dbLabel := db.AssertExistsAndLoadBean(t, &models.Label{ID: apiLabel.ID, OrgID: owner.ID}).(*models.Label)
 	assert.EqualValues(t, dbLabel.Name, apiLabel.Name)
 	assert.EqualValues(t, strings.TrimLeft(dbLabel.Color, "#"), apiLabel.Color)
 
diff --git a/integrations/api_issue_milestone_test.go b/integrations/api_issue_milestone_test.go
index b9942d9a3..ba4ada121 100644
--- a/integrations/api_issue_milestone_test.go
+++ b/integrations/api_issue_milestone_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -18,9 +19,9 @@ import (
 func TestAPIIssuesMilestone(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	milestone := models.AssertExistsAndLoadBean(t, &models.Milestone{ID: 1}).(*models.Milestone)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: milestone.RepoID}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	milestone := db.AssertExistsAndLoadBean(t, &models.Milestone{ID: 1}).(*models.Milestone)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: milestone.RepoID}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 	assert.Equal(t, int64(1), int64(milestone.NumIssues))
 	assert.Equal(t, structs.StateOpen, milestone.State())
 
diff --git a/integrations/api_issue_reaction_test.go b/integrations/api_issue_reaction_test.go
index ad4adc1ea..d064f4885 100644
--- a/integrations/api_issue_reaction_test.go
+++ b/integrations/api_issue_reaction_test.go
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/convert"
 	api "code.gitea.io/gitea/modules/structs"
 
@@ -20,14 +21,14 @@ import (
 func TestAPIIssuesReactions(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	issue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 1}).(*models.Issue)
+	issue := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 1}).(*models.Issue)
 	_ = issue.LoadRepo()
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: issue.Repo.OwnerID}).(*models.User)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: issue.Repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, owner.Name)
 	token := getTokenForLoggedInUser(t, session)
 
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	urlStr := fmt.Sprintf("/api/v1/repos/%s/%s/issues/%d/reactions?token=%s",
 		owner.Name, issue.Repo.Name, issue.Index, token)
 
@@ -77,17 +78,17 @@ func TestAPIIssuesReactions(t *testing.T) {
 func TestAPICommentReactions(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	comment := models.AssertExistsAndLoadBean(t, &models.Comment{ID: 2}).(*models.Comment)
+	comment := db.AssertExistsAndLoadBean(t, &models.Comment{ID: 2}).(*models.Comment)
 	_ = comment.LoadIssue()
 	issue := comment.Issue
 	_ = issue.LoadRepo()
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: issue.Repo.OwnerID}).(*models.User)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: issue.Repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, owner.Name)
 	token := getTokenForLoggedInUser(t, session)
 
-	user1 := models.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user1 := db.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	urlStr := fmt.Sprintf("/api/v1/repos/%s/%s/issues/comments/%d/reactions?token=%s",
 		owner.Name, issue.Repo.Name, comment.ID, token)
 
diff --git a/integrations/api_issue_stopwatch_test.go b/integrations/api_issue_stopwatch_test.go
index c0b8fd9c6..8ccd79f69 100644
--- a/integrations/api_issue_stopwatch_test.go
+++ b/integrations/api_issue_stopwatch_test.go
@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -17,8 +18,8 @@ import (
 func TestAPIListStopWatches(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, owner.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -26,8 +27,8 @@ func TestAPIListStopWatches(t *testing.T) {
 	resp := session.MakeRequest(t, req, http.StatusOK)
 	var apiWatches []*api.StopWatch
 	DecodeJSON(t, resp, &apiWatches)
-	stopwatch := models.AssertExistsAndLoadBean(t, &models.Stopwatch{UserID: owner.ID}).(*models.Stopwatch)
-	issue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: stopwatch.IssueID}).(*models.Issue)
+	stopwatch := db.AssertExistsAndLoadBean(t, &models.Stopwatch{UserID: owner.ID}).(*models.Stopwatch)
+	issue := db.AssertExistsAndLoadBean(t, &models.Issue{ID: stopwatch.IssueID}).(*models.Issue)
 	if assert.Len(t, apiWatches, 1) {
 		assert.EqualValues(t, stopwatch.CreatedUnix.AsTime().Unix(), apiWatches[0].Created.Unix())
 		assert.EqualValues(t, issue.Index, apiWatches[0].IssueIndex)
@@ -41,10 +42,10 @@ func TestAPIListStopWatches(t *testing.T) {
 func TestAPIStopStopWatches(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	issue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 2}).(*models.Issue)
+	issue := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 2}).(*models.Issue)
 	_ = issue.LoadRepo()
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: issue.Repo.OwnerID}).(*models.User)
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: issue.Repo.OwnerID}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -57,10 +58,10 @@ func TestAPIStopStopWatches(t *testing.T) {
 func TestAPICancelStopWatches(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	issue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 1}).(*models.Issue)
+	issue := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 1}).(*models.Issue)
 	_ = issue.LoadRepo()
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: issue.Repo.OwnerID}).(*models.User)
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: issue.Repo.OwnerID}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
 
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -73,10 +74,10 @@ func TestAPICancelStopWatches(t *testing.T) {
 func TestAPIStartStopWatches(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	issue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 3}).(*models.Issue)
+	issue := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 3}).(*models.Issue)
 	_ = issue.LoadRepo()
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: issue.Repo.OwnerID}).(*models.User)
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: issue.Repo.OwnerID}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
diff --git a/integrations/api_issue_subscription_test.go b/integrations/api_issue_subscription_test.go
index d0b192101..30c307661 100644
--- a/integrations/api_issue_subscription_test.go
+++ b/integrations/api_issue_subscription_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -18,20 +19,20 @@ import (
 func TestAPIIssueSubscriptions(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	issue1 := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 1}).(*models.Issue)
-	issue2 := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 2}).(*models.Issue)
-	issue3 := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 3}).(*models.Issue)
-	issue4 := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 4}).(*models.Issue)
-	issue5 := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 8}).(*models.Issue)
+	issue1 := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 1}).(*models.Issue)
+	issue2 := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 2}).(*models.Issue)
+	issue3 := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 3}).(*models.Issue)
+	issue4 := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 4}).(*models.Issue)
+	issue5 := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 8}).(*models.Issue)
 
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: issue1.PosterID}).(*models.User)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: issue1.PosterID}).(*models.User)
 
 	session := loginUser(t, owner.Name)
 	token := getTokenForLoggedInUser(t, session)
 
 	testSubscription := func(issue *models.Issue, isWatching bool) {
 
-		issueRepo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: issue.RepoID}).(*models.Repository)
+		issueRepo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: issue.RepoID}).(*models.Repository)
 
 		urlStr := fmt.Sprintf("/api/v1/repos/%s/%s/issues/%d/subscriptions/check?token=%s", issueRepo.OwnerName, issueRepo.Name, issue.Index, token)
 		req := NewRequest(t, "GET", urlStr)
@@ -52,7 +53,7 @@ func TestAPIIssueSubscriptions(t *testing.T) {
 	testSubscription(issue4, false)
 	testSubscription(issue5, false)
 
-	issue1Repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: issue1.RepoID}).(*models.Repository)
+	issue1Repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: issue1.RepoID}).(*models.Repository)
 	urlStr := fmt.Sprintf("/api/v1/repos/%s/%s/issues/%d/subscriptions/%s?token=%s", issue1Repo.OwnerName, issue1Repo.Name, issue1.Index, owner.Name, token)
 	req := NewRequest(t, "DELETE", urlStr)
 	session.MakeRequest(t, req, http.StatusCreated)
@@ -62,7 +63,7 @@ func TestAPIIssueSubscriptions(t *testing.T) {
 	session.MakeRequest(t, req, http.StatusOK)
 	testSubscription(issue1, false)
 
-	issue5Repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: issue5.RepoID}).(*models.Repository)
+	issue5Repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: issue5.RepoID}).(*models.Repository)
 	urlStr = fmt.Sprintf("/api/v1/repos/%s/%s/issues/%d/subscriptions/%s?token=%s", issue5Repo.OwnerName, issue5Repo.Name, issue5.Index, owner.Name, token)
 	req = NewRequest(t, "PUT", urlStr)
 	session.MakeRequest(t, req, http.StatusCreated)
diff --git a/integrations/api_issue_test.go b/integrations/api_issue_test.go
index 245ab76c7..df258a983 100644
--- a/integrations/api_issue_test.go
+++ b/integrations/api_issue_test.go
@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -20,8 +21,8 @@ import (
 func TestAPIListIssues(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, owner.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -31,9 +32,9 @@ func TestAPIListIssues(t *testing.T) {
 	resp := session.MakeRequest(t, NewRequest(t, "GET", link.String()), http.StatusOK)
 	var apiIssues []*api.Issue
 	DecodeJSON(t, resp, &apiIssues)
-	assert.Len(t, apiIssues, models.GetCount(t, &models.Issue{RepoID: repo.ID}))
+	assert.Len(t, apiIssues, db.GetCount(t, &models.Issue{RepoID: repo.ID}))
 	for _, apiIssue := range apiIssues {
-		models.AssertExistsAndLoadBean(t, &models.Issue{ID: apiIssue.ID, RepoID: repo.ID})
+		db.AssertExistsAndLoadBean(t, &models.Issue{ID: apiIssue.ID, RepoID: repo.ID})
 	}
 
 	// test milestone filter
@@ -71,8 +72,8 @@ func TestAPICreateIssue(t *testing.T) {
 	defer prepareTestEnv(t)()
 	const body, title = "apiTestBody", "apiTestTitle"
 
-	repoBefore := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repoBefore.OwnerID}).(*models.User)
+	repoBefore := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repoBefore.OwnerID}).(*models.User)
 
 	session := loginUser(t, owner.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -88,14 +89,14 @@ func TestAPICreateIssue(t *testing.T) {
 	assert.Equal(t, body, apiIssue.Body)
 	assert.Equal(t, title, apiIssue.Title)
 
-	models.AssertExistsAndLoadBean(t, &models.Issue{
+	db.AssertExistsAndLoadBean(t, &models.Issue{
 		RepoID:     repoBefore.ID,
 		AssigneeID: owner.ID,
 		Content:    body,
 		Title:      title,
 	})
 
-	repoAfter := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	repoAfter := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 	assert.Equal(t, repoBefore.NumIssues+1, repoAfter.NumIssues)
 	assert.Equal(t, repoBefore.NumClosedIssues, repoAfter.NumClosedIssues)
 }
@@ -103,9 +104,9 @@ func TestAPICreateIssue(t *testing.T) {
 func TestAPIEditIssue(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	issueBefore := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 10}).(*models.Issue)
-	repoBefore := models.AssertExistsAndLoadBean(t, &models.Repository{ID: issueBefore.RepoID}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repoBefore.OwnerID}).(*models.User)
+	issueBefore := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 10}).(*models.Issue)
+	repoBefore := db.AssertExistsAndLoadBean(t, &models.Repository{ID: issueBefore.RepoID}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repoBefore.OwnerID}).(*models.User)
 	assert.NoError(t, issueBefore.LoadAttributes())
 	assert.Equal(t, int64(1019307200), int64(issueBefore.DeadlineUnix))
 	assert.Equal(t, api.StateOpen, issueBefore.State())
@@ -134,8 +135,8 @@ func TestAPIEditIssue(t *testing.T) {
 	var apiIssue api.Issue
 	DecodeJSON(t, resp, &apiIssue)
 
-	issueAfter := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 10}).(*models.Issue)
-	repoAfter := models.AssertExistsAndLoadBean(t, &models.Repository{ID: issueBefore.RepoID}).(*models.Repository)
+	issueAfter := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 10}).(*models.Issue)
+	repoAfter := db.AssertExistsAndLoadBean(t, &models.Repository{ID: issueBefore.RepoID}).(*models.Repository)
 
 	// check deleted user
 	assert.Equal(t, int64(500), issueAfter.PosterID)
diff --git a/integrations/api_issue_tracked_time_test.go b/integrations/api_issue_tracked_time_test.go
index 9731c5a93..fcf18e45d 100644
--- a/integrations/api_issue_tracked_time_test.go
+++ b/integrations/api_issue_tracked_time_test.go
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -19,8 +20,8 @@ import (
 func TestAPIGetTrackedTimes(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	issue2 := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 2}).(*models.Issue)
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	issue2 := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 2}).(*models.Issue)
 	assert.NoError(t, issue2.LoadRepo())
 
 	session := loginUser(t, user2.Name)
@@ -61,10 +62,10 @@ func TestAPIGetTrackedTimes(t *testing.T) {
 func TestAPIDeleteTrackedTime(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	time6 := models.AssertExistsAndLoadBean(t, &models.TrackedTime{ID: 6}).(*models.TrackedTime)
-	issue2 := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 2}).(*models.Issue)
+	time6 := db.AssertExistsAndLoadBean(t, &models.TrackedTime{ID: 6}).(*models.TrackedTime)
+	issue2 := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 2}).(*models.Issue)
 	assert.NoError(t, issue2.LoadRepo())
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 
 	session := loginUser(t, user2.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -73,7 +74,7 @@ func TestAPIDeleteTrackedTime(t *testing.T) {
 	req := NewRequestf(t, "DELETE", "/api/v1/repos/%s/%s/issues/%d/times/%d?token=%s", user2.Name, issue2.Repo.Name, issue2.Index, time6.ID, token)
 	session.MakeRequest(t, req, http.StatusForbidden)
 
-	time3 := models.AssertExistsAndLoadBean(t, &models.TrackedTime{ID: 3}).(*models.TrackedTime)
+	time3 := db.AssertExistsAndLoadBean(t, &models.TrackedTime{ID: 3}).(*models.TrackedTime)
 	req = NewRequestf(t, "DELETE", "/api/v1/repos/%s/%s/issues/%d/times/%d?token=%s", user2.Name, issue2.Repo.Name, issue2.Index, time3.ID, token)
 	session.MakeRequest(t, req, http.StatusNoContent)
 	//Delete non existing time
@@ -96,10 +97,10 @@ func TestAPIDeleteTrackedTime(t *testing.T) {
 func TestAPIAddTrackedTimes(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	issue2 := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 2}).(*models.Issue)
+	issue2 := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 2}).(*models.Issue)
 	assert.NoError(t, issue2.LoadRepo())
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	admin := models.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	admin := db.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
 
 	session := loginUser(t, admin.Name)
 	token := getTokenForLoggedInUser(t, session)
diff --git a/integrations/api_keys_test.go b/integrations/api_keys_test.go
index 50e1e7a35..161b05e8c 100644
--- a/integrations/api_keys_test.go
+++ b/integrations/api_keys_test.go
@@ -11,6 +11,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -45,8 +46,8 @@ func TestDeleteDeployKeyNoLogin(t *testing.T) {
 
 func TestCreateReadOnlyDeployKey(t *testing.T) {
 	defer prepareTestEnv(t)()
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{Name: "repo1"}).(*models.Repository)
-	repoOwner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{Name: "repo1"}).(*models.Repository)
+	repoOwner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, repoOwner.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -61,7 +62,7 @@ func TestCreateReadOnlyDeployKey(t *testing.T) {
 
 	var newDeployKey api.DeployKey
 	DecodeJSON(t, resp, &newDeployKey)
-	models.AssertExistsAndLoadBean(t, &models.DeployKey{
+	db.AssertExistsAndLoadBean(t, &models.DeployKey{
 		ID:      newDeployKey.ID,
 		Name:    rawKeyBody.Title,
 		Content: rawKeyBody.Key,
@@ -71,8 +72,8 @@ func TestCreateReadOnlyDeployKey(t *testing.T) {
 
 func TestCreateReadWriteDeployKey(t *testing.T) {
 	defer prepareTestEnv(t)()
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{Name: "repo1"}).(*models.Repository)
-	repoOwner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{Name: "repo1"}).(*models.Repository)
+	repoOwner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, repoOwner.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -86,7 +87,7 @@ func TestCreateReadWriteDeployKey(t *testing.T) {
 
 	var newDeployKey api.DeployKey
 	DecodeJSON(t, resp, &newDeployKey)
-	models.AssertExistsAndLoadBean(t, &models.DeployKey{
+	db.AssertExistsAndLoadBean(t, &models.DeployKey{
 		ID:      newDeployKey.ID,
 		Name:    rawKeyBody.Title,
 		Content: rawKeyBody.Key,
@@ -96,7 +97,7 @@ func TestCreateReadWriteDeployKey(t *testing.T) {
 
 func TestCreateUserKey(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user := models.AssertExistsAndLoadBean(t, &models.User{Name: "user1"}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{Name: "user1"}).(*models.User)
 
 	session := loginUser(t, "user1")
 	token := url.QueryEscape(getTokenForLoggedInUser(t, session))
@@ -112,7 +113,7 @@ func TestCreateUserKey(t *testing.T) {
 
 	var newPublicKey api.PublicKey
 	DecodeJSON(t, resp, &newPublicKey)
-	models.AssertExistsAndLoadBean(t, &models.PublicKey{
+	db.AssertExistsAndLoadBean(t, &models.PublicKey{
 		ID:      newPublicKey.ID,
 		OwnerID: user.ID,
 		Name:    rawKeyBody.Title,
diff --git a/integrations/api_notification_test.go b/integrations/api_notification_test.go
index 96af14fb8..3049f1b99 100644
--- a/integrations/api_notification_test.go
+++ b/integrations/api_notification_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -18,9 +19,9 @@ import (
 func TestAPINotification(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	repo1 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	thread5 := models.AssertExistsAndLoadBean(t, &models.Notification{ID: 5}).(*models.Notification)
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo1 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	thread5 := db.AssertExistsAndLoadBean(t, &models.Notification{ID: 5}).(*models.Notification)
 	assert.NoError(t, thread5.LoadAttributes())
 	session := loginUser(t, user2.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -111,7 +112,7 @@ func TestAPINotification(t *testing.T) {
 	resp = session.MakeRequest(t, req, http.StatusResetContent)
 
 	assert.Equal(t, models.NotificationStatusUnread, thread5.Status)
-	thread5 = models.AssertExistsAndLoadBean(t, &models.Notification{ID: 5}).(*models.Notification)
+	thread5 = db.AssertExistsAndLoadBean(t, &models.Notification{ID: 5}).(*models.Notification)
 	assert.Equal(t, models.NotificationStatusRead, thread5.Status)
 
 	// -- check notifications --
diff --git a/integrations/api_oauth2_apps_test.go b/integrations/api_oauth2_apps_test.go
index 5c90dbb3b..4cda41755 100644
--- a/integrations/api_oauth2_apps_test.go
+++ b/integrations/api_oauth2_apps_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -25,7 +26,7 @@ func TestOAuth2Application(t *testing.T) {
 }
 
 func testAPICreateOAuth2Application(t *testing.T) {
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	appBody := api.CreateOAuth2ApplicationOptions{
 		Name: "test-app-1",
 		RedirectURIs: []string{
@@ -45,15 +46,15 @@ func testAPICreateOAuth2Application(t *testing.T) {
 	assert.Len(t, createdApp.ClientID, 36)
 	assert.NotEmpty(t, createdApp.Created)
 	assert.EqualValues(t, appBody.RedirectURIs[0], createdApp.RedirectURIs[0])
-	models.AssertExistsAndLoadBean(t, &models.OAuth2Application{UID: user.ID, Name: createdApp.Name})
+	db.AssertExistsAndLoadBean(t, &models.OAuth2Application{UID: user.ID, Name: createdApp.Name})
 }
 
 func testAPIListOAuth2Applications(t *testing.T) {
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
 
-	existApp := models.AssertExistsAndLoadBean(t, &models.OAuth2Application{
+	existApp := db.AssertExistsAndLoadBean(t, &models.OAuth2Application{
 		UID:  user.ID,
 		Name: "test-app-1",
 		RedirectURIs: []string{
@@ -74,15 +75,15 @@ func testAPIListOAuth2Applications(t *testing.T) {
 	assert.Len(t, expectedApp.ClientID, 36)
 	assert.Empty(t, expectedApp.ClientSecret)
 	assert.EqualValues(t, existApp.RedirectURIs[0], expectedApp.RedirectURIs[0])
-	models.AssertExistsAndLoadBean(t, &models.OAuth2Application{ID: expectedApp.ID, Name: expectedApp.Name})
+	db.AssertExistsAndLoadBean(t, &models.OAuth2Application{ID: expectedApp.ID, Name: expectedApp.Name})
 }
 
 func testAPIDeleteOAuth2Application(t *testing.T) {
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
 
-	oldApp := models.AssertExistsAndLoadBean(t, &models.OAuth2Application{
+	oldApp := db.AssertExistsAndLoadBean(t, &models.OAuth2Application{
 		UID:  user.ID,
 		Name: "test-app-1",
 	}).(*models.OAuth2Application)
@@ -91,7 +92,7 @@ func testAPIDeleteOAuth2Application(t *testing.T) {
 	req := NewRequest(t, "DELETE", urlStr)
 	session.MakeRequest(t, req, http.StatusNoContent)
 
-	models.AssertNotExistsBean(t, &models.OAuth2Application{UID: oldApp.UID, Name: oldApp.Name})
+	db.AssertNotExistsBean(t, &models.OAuth2Application{UID: oldApp.UID, Name: oldApp.Name})
 
 	// Delete again will return not found
 	req = NewRequest(t, "DELETE", urlStr)
@@ -99,11 +100,11 @@ func testAPIDeleteOAuth2Application(t *testing.T) {
 }
 
 func testAPIGetOAuth2Application(t *testing.T) {
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
 
-	existApp := models.AssertExistsAndLoadBean(t, &models.OAuth2Application{
+	existApp := db.AssertExistsAndLoadBean(t, &models.OAuth2Application{
 		UID:  user.ID,
 		Name: "test-app-1",
 		RedirectURIs: []string{
@@ -125,13 +126,13 @@ func testAPIGetOAuth2Application(t *testing.T) {
 	assert.Empty(t, expectedApp.ClientSecret)
 	assert.Len(t, expectedApp.RedirectURIs, 1)
 	assert.EqualValues(t, existApp.RedirectURIs[0], expectedApp.RedirectURIs[0])
-	models.AssertExistsAndLoadBean(t, &models.OAuth2Application{ID: expectedApp.ID, Name: expectedApp.Name})
+	db.AssertExistsAndLoadBean(t, &models.OAuth2Application{ID: expectedApp.ID, Name: expectedApp.Name})
 }
 
 func testAPIUpdateOAuth2Application(t *testing.T) {
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 
-	existApp := models.AssertExistsAndLoadBean(t, &models.OAuth2Application{
+	existApp := db.AssertExistsAndLoadBean(t, &models.OAuth2Application{
 		UID:  user.ID,
 		Name: "test-app-1",
 		RedirectURIs: []string{
@@ -159,5 +160,5 @@ func testAPIUpdateOAuth2Application(t *testing.T) {
 	assert.Len(t, expectedApp.RedirectURIs, 2)
 	assert.EqualValues(t, expectedApp.RedirectURIs[0], appBody.RedirectURIs[0])
 	assert.EqualValues(t, expectedApp.RedirectURIs[1], appBody.RedirectURIs[1])
-	models.AssertExistsAndLoadBean(t, &models.OAuth2Application{ID: expectedApp.ID, Name: expectedApp.Name})
+	db.AssertExistsAndLoadBean(t, &models.OAuth2Application{ID: expectedApp.ID, Name: expectedApp.Name})
 }
diff --git a/integrations/api_org_test.go b/integrations/api_org_test.go
index bc4428b99..6268fa4a1 100644
--- a/integrations/api_org_test.go
+++ b/integrations/api_org_test.go
@@ -11,6 +11,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
 
@@ -43,7 +44,7 @@ func TestAPIOrgCreate(t *testing.T) {
 		assert.Equal(t, org.Location, apiOrg.Location)
 		assert.Equal(t, org.Visibility, apiOrg.Visibility)
 
-		models.AssertExistsAndLoadBean(t, &models.User{
+		db.AssertExistsAndLoadBean(t, &models.User{
 			Name:      org.UserName,
 			LowerName: strings.ToLower(org.UserName),
 			FullName:  org.FullName,
diff --git a/integrations/api_pull_commits_test.go b/integrations/api_pull_commits_test.go
index 30682d9c1..615589fd1 100644
--- a/integrations/api_pull_commits_test.go
+++ b/integrations/api_pull_commits_test.go
@@ -9,15 +9,16 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestAPIPullCommits(t *testing.T) {
 	defer prepareTestEnv(t)()
-	pullIssue := models.AssertExistsAndLoadBean(t, &models.PullRequest{ID: 2}).(*models.PullRequest)
+	pullIssue := db.AssertExistsAndLoadBean(t, &models.PullRequest{ID: 2}).(*models.PullRequest)
 	assert.NoError(t, pullIssue.LoadIssue())
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: pullIssue.HeadRepoID}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: pullIssue.HeadRepoID}).(*models.Repository)
 
 	session := loginUser(t, "user2")
 	req := NewRequestf(t, http.MethodGet, "/api/v1/repos/%s/%s/pulls/%d/commits", repo.OwnerName, repo.Name, pullIssue.Index)
diff --git a/integrations/api_pull_review_test.go b/integrations/api_pull_review_test.go
index b0e380376..123ba0a2b 100644
--- a/integrations/api_pull_review_test.go
+++ b/integrations/api_pull_review_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/json"
 	api "code.gitea.io/gitea/modules/structs"
 
@@ -18,9 +19,9 @@ import (
 
 func TestAPIPullReview(t *testing.T) {
 	defer prepareTestEnv(t)()
-	pullIssue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 3}).(*models.Issue)
+	pullIssue := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 3}).(*models.Issue)
 	assert.NoError(t, pullIssue.LoadAttributes())
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: pullIssue.RepoID}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: pullIssue.RepoID}).(*models.Repository)
 
 	// test ListPullReviews
 	session := loginUser(t, "user2")
@@ -62,7 +63,7 @@ func TestAPIPullReview(t *testing.T) {
 	assert.EqualValues(t, *reviews[5], review)
 
 	// test GetPullReviewComments
-	comment := models.AssertExistsAndLoadBean(t, &models.Comment{ID: 7}).(*models.Comment)
+	comment := db.AssertExistsAndLoadBean(t, &models.Comment{ID: 7}).(*models.Comment)
 	req = NewRequestf(t, http.MethodGet, "/api/v1/repos/%s/%s/pulls/%d/reviews/%d/comments?token=%s", repo.OwnerName, repo.Name, pullIssue.Index, 10, token)
 	resp = session.MakeRequest(t, req, http.StatusOK)
 	var reviewComments []*api.PullReviewComment
@@ -195,9 +196,9 @@ func TestAPIPullReview(t *testing.T) {
 
 	// test get review requests
 	// to make it simple, use same api with get review
-	pullIssue12 := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 12}).(*models.Issue)
+	pullIssue12 := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 12}).(*models.Issue)
 	assert.NoError(t, pullIssue12.LoadAttributes())
-	repo3 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: pullIssue12.RepoID}).(*models.Repository)
+	repo3 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: pullIssue12.RepoID}).(*models.Repository)
 
 	req = NewRequestf(t, http.MethodGet, "/api/v1/repos/%s/%s/pulls/%d/reviews?token=%s", repo3.OwnerName, repo3.Name, pullIssue12.Index, token)
 	resp = session.MakeRequest(t, req, http.StatusOK)
@@ -219,9 +220,9 @@ func TestAPIPullReview(t *testing.T) {
 
 func TestAPIPullReviewRequest(t *testing.T) {
 	defer prepareTestEnv(t)()
-	pullIssue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 3}).(*models.Issue)
+	pullIssue := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 3}).(*models.Issue)
 	assert.NoError(t, pullIssue.LoadAttributes())
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: pullIssue.RepoID}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: pullIssue.RepoID}).(*models.Repository)
 
 	// Test add Review Request
 	session := loginUser(t, "user2")
@@ -264,9 +265,9 @@ func TestAPIPullReviewRequest(t *testing.T) {
 	session.MakeRequest(t, req, http.StatusNoContent)
 
 	// Test team review request
-	pullIssue12 := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 12}).(*models.Issue)
+	pullIssue12 := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 12}).(*models.Issue)
 	assert.NoError(t, pullIssue12.LoadAttributes())
-	repo3 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: pullIssue12.RepoID}).(*models.Repository)
+	repo3 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: pullIssue12.RepoID}).(*models.Repository)
 
 	// Test add Team Review Request
 	req = NewRequestWithJSON(t, http.MethodPost, fmt.Sprintf("/api/v1/repos/%s/%s/pulls/%d/requested_reviewers?token=%s", repo3.OwnerName, repo3.Name, pullIssue12.Index, token), &api.PullReviewRequestOptions{
diff --git a/integrations/api_pull_test.go b/integrations/api_pull_test.go
index e6a4aca15..069650993 100644
--- a/integrations/api_pull_test.go
+++ b/integrations/api_pull_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/services/forms"
@@ -20,8 +21,8 @@ import (
 
 func TestAPIViewPulls(t *testing.T) {
 	defer prepareTestEnv(t)()
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, "user2")
 	token := getTokenForLoggedInUser(t, session)
@@ -30,16 +31,16 @@ func TestAPIViewPulls(t *testing.T) {
 
 	var pulls []*api.PullRequest
 	DecodeJSON(t, resp, &pulls)
-	expectedLen := models.GetCount(t, &models.Issue{RepoID: repo.ID}, models.Cond("is_pull = ?", true))
+	expectedLen := db.GetCount(t, &models.Issue{RepoID: repo.ID}, db.Cond("is_pull = ?", true))
 	assert.Len(t, pulls, expectedLen)
 }
 
 // TestAPIMergePullWIP ensures that we can't merge a WIP pull request
 func TestAPIMergePullWIP(t *testing.T) {
 	defer prepareTestEnv(t)()
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
-	pr := models.AssertExistsAndLoadBean(t, &models.PullRequest{Status: models.PullRequestStatusMergeable}, models.Cond("has_merged = ?", false)).(*models.PullRequest)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	pr := db.AssertExistsAndLoadBean(t, &models.PullRequest{Status: models.PullRequestStatusMergeable}, db.Cond("has_merged = ?", false)).(*models.PullRequest)
 	pr.LoadIssue()
 	issue_service.ChangeTitle(pr.Issue, owner, setting.Repository.PullRequest.WorkInProgressPrefixes[0]+" "+pr.Issue.Title)
 
@@ -60,12 +61,12 @@ func TestAPIMergePullWIP(t *testing.T) {
 
 func TestAPICreatePullSuccess(t *testing.T) {
 	defer prepareTestEnv(t)()
-	repo10 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 10}).(*models.Repository)
+	repo10 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 10}).(*models.Repository)
 	// repo10 have code, pulls units.
-	repo11 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 11}).(*models.Repository)
+	repo11 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 11}).(*models.Repository)
 	// repo11 only have code unit but should still create pulls
-	owner10 := models.AssertExistsAndLoadBean(t, &models.User{ID: repo10.OwnerID}).(*models.User)
-	owner11 := models.AssertExistsAndLoadBean(t, &models.User{ID: repo11.OwnerID}).(*models.User)
+	owner10 := db.AssertExistsAndLoadBean(t, &models.User{ID: repo10.OwnerID}).(*models.User)
+	owner11 := db.AssertExistsAndLoadBean(t, &models.User{ID: repo11.OwnerID}).(*models.User)
 
 	session := loginUser(t, owner11.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -81,11 +82,11 @@ func TestAPICreatePullSuccess(t *testing.T) {
 func TestAPICreatePullWithFieldsSuccess(t *testing.T) {
 	defer prepareTestEnv(t)()
 	// repo10 have code, pulls units.
-	repo10 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 10}).(*models.Repository)
-	owner10 := models.AssertExistsAndLoadBean(t, &models.User{ID: repo10.OwnerID}).(*models.User)
+	repo10 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 10}).(*models.Repository)
+	owner10 := db.AssertExistsAndLoadBean(t, &models.User{ID: repo10.OwnerID}).(*models.User)
 	// repo11 only have code unit but should still create pulls
-	repo11 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 11}).(*models.Repository)
-	owner11 := models.AssertExistsAndLoadBean(t, &models.User{ID: repo11.OwnerID}).(*models.User)
+	repo11 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 11}).(*models.Repository)
+	owner11 := db.AssertExistsAndLoadBean(t, &models.User{ID: repo11.OwnerID}).(*models.User)
 
 	session := loginUser(t, owner11.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -118,11 +119,11 @@ func TestAPICreatePullWithFieldsSuccess(t *testing.T) {
 func TestAPICreatePullWithFieldsFailure(t *testing.T) {
 	defer prepareTestEnv(t)()
 	// repo10 have code, pulls units.
-	repo10 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 10}).(*models.Repository)
-	owner10 := models.AssertExistsAndLoadBean(t, &models.User{ID: repo10.OwnerID}).(*models.User)
+	repo10 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 10}).(*models.Repository)
+	owner10 := db.AssertExistsAndLoadBean(t, &models.User{ID: repo10.OwnerID}).(*models.User)
 	// repo11 only have code unit but should still create pulls
-	repo11 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 11}).(*models.Repository)
-	owner11 := models.AssertExistsAndLoadBean(t, &models.User{ID: repo11.OwnerID}).(*models.User)
+	repo11 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 11}).(*models.Repository)
+	owner11 := db.AssertExistsAndLoadBean(t, &models.User{ID: repo11.OwnerID}).(*models.User)
 
 	session := loginUser(t, owner11.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -151,8 +152,8 @@ func TestAPICreatePullWithFieldsFailure(t *testing.T) {
 
 func TestAPIEditPull(t *testing.T) {
 	defer prepareTestEnv(t)()
-	repo10 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 10}).(*models.Repository)
-	owner10 := models.AssertExistsAndLoadBean(t, &models.User{ID: repo10.OwnerID}).(*models.User)
+	repo10 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 10}).(*models.Repository)
+	owner10 := db.AssertExistsAndLoadBean(t, &models.User{ID: repo10.OwnerID}).(*models.User)
 
 	session := loginUser(t, owner10.Name)
 	token := getTokenForLoggedInUser(t, session)
diff --git a/integrations/api_releases_test.go b/integrations/api_releases_test.go
index 027b28203..cb04c2a8d 100644
--- a/integrations/api_releases_test.go
+++ b/integrations/api_releases_test.go
@@ -11,6 +11,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	api "code.gitea.io/gitea/modules/structs"
 
@@ -20,8 +21,8 @@ import (
 func TestAPIListReleases(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	session := loginUser(t, user2.LowerName)
 	token := getTokenForLoggedInUser(t, session)
 
@@ -84,7 +85,7 @@ func createNewReleaseUsingAPI(t *testing.T, session *TestSession, token string,
 
 	var newRelease api.Release
 	DecodeJSON(t, resp, &newRelease)
-	models.AssertExistsAndLoadBean(t, &models.Release{
+	db.AssertExistsAndLoadBean(t, &models.Release{
 		ID:      newRelease.ID,
 		TagName: newRelease.TagName,
 		Title:   newRelease.Title,
@@ -97,8 +98,8 @@ func createNewReleaseUsingAPI(t *testing.T, session *TestSession, token string,
 func TestAPICreateAndUpdateRelease(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 	session := loginUser(t, owner.LowerName)
 	token := getTokenForLoggedInUser(t, session)
 
@@ -137,7 +138,7 @@ func TestAPICreateAndUpdateRelease(t *testing.T) {
 	resp = session.MakeRequest(t, req, http.StatusOK)
 
 	DecodeJSON(t, resp, &newRelease)
-	models.AssertExistsAndLoadBean(t, &models.Release{
+	db.AssertExistsAndLoadBean(t, &models.Release{
 		ID:      newRelease.ID,
 		TagName: newRelease.TagName,
 		Title:   newRelease.Title,
@@ -148,8 +149,8 @@ func TestAPICreateAndUpdateRelease(t *testing.T) {
 func TestAPICreateReleaseToDefaultBranch(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 	session := loginUser(t, owner.LowerName)
 	token := getTokenForLoggedInUser(t, session)
 
@@ -159,8 +160,8 @@ func TestAPICreateReleaseToDefaultBranch(t *testing.T) {
 func TestAPICreateReleaseToDefaultBranchOnExistingTag(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 	session := loginUser(t, owner.LowerName)
 	token := getTokenForLoggedInUser(t, session)
 
@@ -177,8 +178,8 @@ func TestAPICreateReleaseToDefaultBranchOnExistingTag(t *testing.T) {
 func TestAPIGetReleaseByTag(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 	session := loginUser(t, owner.LowerName)
 
 	tag := "v1.1"
@@ -210,8 +211,8 @@ func TestAPIGetReleaseByTag(t *testing.T) {
 func TestAPIDeleteReleaseByTagName(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 	session := loginUser(t, owner.LowerName)
 	token := getTokenForLoggedInUser(t, session)
 
diff --git a/integrations/api_repo_edit_test.go b/integrations/api_repo_edit_test.go
index 618c1f0ad..e980357a0 100644
--- a/integrations/api_repo_edit_test.go
+++ b/integrations/api_repo_edit_test.go
@@ -11,6 +11,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -132,13 +133,13 @@ func TestAPIRepoEdit(t *testing.T) {
 	onGiteaRun(t, func(t *testing.T, u *url.URL) {
 		bFalse, bTrue := false, true
 
-		user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)               // owner of the repo1 & repo16
-		user3 := models.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)               // owner of the repo3, is an org
-		user4 := models.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)               // owner of neither repos
-		repo1 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)   // public repo
-		repo3 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)   // public repo
-		repo15 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 15}).(*models.Repository) // empty repo
-		repo16 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository) // private repo
+		user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)               // owner of the repo1 & repo16
+		user3 := db.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)               // owner of the repo3, is an org
+		user4 := db.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)               // owner of neither repos
+		repo1 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)   // public repo
+		repo3 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)   // public repo
+		repo15 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 15}).(*models.Repository) // empty repo
+		repo16 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository) // private repo
 
 		// Get user2's token
 		session := loginUser(t, user2.Name)
@@ -164,7 +165,7 @@ func TestAPIRepoEdit(t *testing.T) {
 		assert.Equal(t, *repoEditOption.Website, repo.Website)
 		assert.Equal(t, *repoEditOption.Archived, repo.Archived)
 		// check repo1 from database
-		repo1edited := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+		repo1edited := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 		repo1editedOption := getRepoEditOptionFromRepo(repo1edited)
 		assert.Equal(t, *repoEditOption.Name, *repo1editedOption.Name)
 		assert.Equal(t, *repoEditOption.Description, *repo1editedOption.Description)
@@ -189,7 +190,7 @@ func TestAPIRepoEdit(t *testing.T) {
 		DecodeJSON(t, resp, &repo)
 		assert.NotNil(t, repo)
 		// check repo1 was written to database
-		repo1edited = models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+		repo1edited = db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 		repo1editedOption = getRepoEditOptionFromRepo(repo1edited)
 		assert.Equal(t, *repo1editedOption.HasIssues, true)
 		assert.Nil(t, repo1editedOption.ExternalTracker)
@@ -211,7 +212,7 @@ func TestAPIRepoEdit(t *testing.T) {
 		DecodeJSON(t, resp, &repo)
 		assert.NotNil(t, repo)
 		// check repo1 was written to database
-		repo1edited = models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+		repo1edited = db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 		repo1editedOption = getRepoEditOptionFromRepo(repo1edited)
 		assert.Equal(t, *repo1editedOption.HasIssues, true)
 		assert.Equal(t, *repo1editedOption.ExternalTracker, *repoEditOption.ExternalTracker)
@@ -242,7 +243,7 @@ func TestAPIRepoEdit(t *testing.T) {
 		DecodeJSON(t, resp, &repo)
 		assert.NotNil(t, repo)
 		// check repo1 was written to database
-		repo1edited = models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+		repo1edited = db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 		repo1editedOption = getRepoEditOptionFromRepo(repo1edited)
 		assert.Equal(t, *repo1editedOption.Description, *repoEditOption.Description)
 		assert.Equal(t, *repo1editedOption.HasIssues, true)
@@ -287,7 +288,7 @@ func TestAPIRepoEdit(t *testing.T) {
 		_ = session.MakeRequest(t, req, http.StatusOK)
 
 		// Test making a repo public that is private
-		repo16 = models.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository)
+		repo16 = db.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository)
 		assert.True(t, repo16.IsPrivate)
 		repoEditOption = &api.EditRepoOption{
 			Private: &bFalse,
@@ -295,7 +296,7 @@ func TestAPIRepoEdit(t *testing.T) {
 		url = fmt.Sprintf("/api/v1/repos/%s/%s?token=%s", user2.Name, repo16.Name, token2)
 		req = NewRequestWithJSON(t, "PATCH", url, &repoEditOption)
 		_ = session.MakeRequest(t, req, http.StatusOK)
-		repo16 = models.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository)
+		repo16 = db.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository)
 		assert.False(t, repo16.IsPrivate)
 		// Make it private again
 		repoEditOption.Private = &bTrue
@@ -309,7 +310,7 @@ func TestAPIRepoEdit(t *testing.T) {
 			Archived: &bTrue,
 		})
 		_ = session.MakeRequest(t, req, http.StatusOK)
-		repo15 = models.AssertExistsAndLoadBean(t, &models.Repository{ID: 15}).(*models.Repository)
+		repo15 = db.AssertExistsAndLoadBean(t, &models.Repository{ID: 15}).(*models.Repository)
 		assert.True(t, repo15.IsArchived)
 		req = NewRequestWithJSON(t, "PATCH", url, &api.EditRepoOption{
 			Archived: &bFalse,
diff --git a/integrations/api_repo_file_create_test.go b/integrations/api_repo_file_create_test.go
index 17ed6cb7c..5b0e3927f 100644
--- a/integrations/api_repo_file_create_test.go
+++ b/integrations/api_repo_file_create_test.go
@@ -14,6 +14,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/setting"
@@ -108,8 +109,8 @@ func getExpectedFileResponseForCreate(commitID, treePath string) *api.FileRespon
 func BenchmarkAPICreateFileSmall(b *testing.B) {
 	onGiteaRunTB(b, func(t testing.TB, u *url.URL) {
 		b := t.(*testing.B)
-		user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)             // owner of the repo1 & repo16
-		repo1 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository) // public repo
+		user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)             // owner of the repo1 & repo16
+		repo1 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository) // public repo
 
 		for n := 0; n < b.N; n++ {
 			treePath := fmt.Sprintf("update/file%d.txt", n)
@@ -123,8 +124,8 @@ func BenchmarkAPICreateFileMedium(b *testing.B) {
 
 	onGiteaRunTB(b, func(t testing.TB, u *url.URL) {
 		b := t.(*testing.B)
-		user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)             // owner of the repo1 & repo16
-		repo1 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository) // public repo
+		user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)             // owner of the repo1 & repo16
+		repo1 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository) // public repo
 
 		b.ResetTimer()
 		for n := 0; n < b.N; n++ {
@@ -137,12 +138,12 @@ func BenchmarkAPICreateFileMedium(b *testing.B) {
 
 func TestAPICreateFile(t *testing.T) {
 	onGiteaRun(t, func(t *testing.T, u *url.URL) {
-		user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)               // owner of the repo1 & repo16
-		user3 := models.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)               // owner of the repo3, is an org
-		user4 := models.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)               // owner of neither repos
-		repo1 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)   // public repo
-		repo3 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)   // public repo
-		repo16 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository) // private repo
+		user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)               // owner of the repo1 & repo16
+		user3 := db.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)               // owner of the repo3, is an org
+		user4 := db.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)               // owner of neither repos
+		repo1 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)   // public repo
+		repo3 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)   // public repo
+		repo16 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository) // private repo
 		fileID := 0
 
 		// Get user2's token
diff --git a/integrations/api_repo_file_delete_test.go b/integrations/api_repo_file_delete_test.go
index 178aec6f5..69e24d29c 100644
--- a/integrations/api_repo_file_delete_test.go
+++ b/integrations/api_repo_file_delete_test.go
@@ -11,6 +11,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -37,12 +38,12 @@ func getDeleteFileOptions() *api.DeleteFileOptions {
 
 func TestAPIDeleteFile(t *testing.T) {
 	onGiteaRun(t, func(t *testing.T, u *url.URL) {
-		user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)               // owner of the repo1 & repo16
-		user3 := models.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)               // owner of the repo3, is an org
-		user4 := models.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)               // owner of neither repos
-		repo1 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)   // public repo
-		repo3 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)   // public repo
-		repo16 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository) // private repo
+		user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)               // owner of the repo1 & repo16
+		user3 := db.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)               // owner of the repo3, is an org
+		user4 := db.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)               // owner of neither repos
+		repo1 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)   // public repo
+		repo3 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)   // public repo
+		repo16 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository) // private repo
 		fileID := 0
 
 		// Get user2's token
diff --git a/integrations/api_repo_file_update_test.go b/integrations/api_repo_file_update_test.go
index 69a946377..b6d9be24f 100644
--- a/integrations/api_repo_file_update_test.go
+++ b/integrations/api_repo_file_update_test.go
@@ -13,6 +13,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/setting"
@@ -103,12 +104,12 @@ func getExpectedFileResponseForUpdate(commitID, treePath string) *api.FileRespon
 
 func TestAPIUpdateFile(t *testing.T) {
 	onGiteaRun(t, func(t *testing.T, u *url.URL) {
-		user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)               // owner of the repo1 & repo16
-		user3 := models.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)               // owner of the repo3, is an org
-		user4 := models.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)               // owner of neither repos
-		repo1 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)   // public repo
-		repo3 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)   // public repo
-		repo16 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository) // private repo
+		user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)               // owner of the repo1 & repo16
+		user3 := db.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)               // owner of the repo3, is an org
+		user4 := db.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)               // owner of neither repos
+		repo1 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)   // public repo
+		repo3 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)   // public repo
+		repo16 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository) // private repo
 		fileID := 0
 
 		// Get user2's token
diff --git a/integrations/api_repo_get_contents_list_test.go b/integrations/api_repo_get_contents_list_test.go
index ddbd877a4..625231a8b 100644
--- a/integrations/api_repo_get_contents_list_test.go
+++ b/integrations/api_repo_get_contents_list_test.go
@@ -11,6 +11,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	repo_module "code.gitea.io/gitea/modules/repository"
 	"code.gitea.io/gitea/modules/setting"
@@ -52,13 +53,13 @@ func TestAPIGetContentsList(t *testing.T) {
 
 func testAPIGetContentsList(t *testing.T, u *url.URL) {
 	/*** SETUP ***/
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)               // owner of the repo1 & repo16
-	user3 := models.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)               // owner of the repo3, is an org
-	user4 := models.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)               // owner of neither repos
-	repo1 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)   // public repo
-	repo3 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)   // public repo
-	repo16 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository) // private repo
-	treePath := ""                                                                               // root dir
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)               // owner of the repo1 & repo16
+	user3 := db.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)               // owner of the repo3, is an org
+	user4 := db.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)               // owner of neither repos
+	repo1 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)   // public repo
+	repo3 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)   // public repo
+	repo16 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository) // private repo
+	treePath := ""                                                                           // root dir
 
 	// Get user2's token
 	session := loginUser(t, user2.Name)
diff --git a/integrations/api_repo_get_contents_test.go b/integrations/api_repo_get_contents_test.go
index 3d4a31be8..e096a718b 100644
--- a/integrations/api_repo_get_contents_test.go
+++ b/integrations/api_repo_get_contents_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	repo_module "code.gitea.io/gitea/modules/repository"
 	"code.gitea.io/gitea/modules/setting"
@@ -53,12 +54,12 @@ func TestAPIGetContents(t *testing.T) {
 
 func testAPIGetContents(t *testing.T, u *url.URL) {
 	/*** SETUP ***/
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)               // owner of the repo1 & repo16
-	user3 := models.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)               // owner of the repo3, is an org
-	user4 := models.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)               // owner of neither repos
-	repo1 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)   // public repo
-	repo3 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)   // public repo
-	repo16 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository) // private repo
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)               // owner of the repo1 & repo16
+	user3 := db.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)               // owner of the repo3, is an org
+	user4 := db.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)               // owner of neither repos
+	repo1 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)   // public repo
+	repo3 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)   // public repo
+	repo16 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository) // private repo
 	treePath := "README.md"
 
 	// Get user2's token
diff --git a/integrations/api_repo_git_blobs_test.go b/integrations/api_repo_git_blobs_test.go
index 675916eea..5bbf13ac4 100644
--- a/integrations/api_repo_git_blobs_test.go
+++ b/integrations/api_repo_git_blobs_test.go
@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -16,12 +17,12 @@ import (
 
 func TestAPIReposGitBlobs(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)               // owner of the repo1 & repo16
-	user3 := models.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)               // owner of the repo3
-	user4 := models.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)               // owner of neither repos
-	repo1 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)   // public repo
-	repo3 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)   // public repo
-	repo16 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository) // private repo
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)               // owner of the repo1 & repo16
+	user3 := db.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)               // owner of the repo3
+	user4 := db.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)               // owner of neither repos
+	repo1 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)   // public repo
+	repo3 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)   // public repo
+	repo16 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository) // private repo
 	repo1ReadmeSHA := "65f1bf27bc3bf70f64657658635e66094edbcb4d"
 	repo3ReadmeSHA := "d56a3073c1dbb7b15963110a049d50cdb5db99fc"
 	repo16ReadmeSHA := "f90451c72ef61a7645293d17b47be7a8e983da57"
diff --git a/integrations/api_repo_git_commits_test.go b/integrations/api_repo_git_commits_test.go
index d6bd5fc62..19dab433d 100644
--- a/integrations/api_repo_git_commits_test.go
+++ b/integrations/api_repo_git_commits_test.go
@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -24,7 +25,7 @@ func compareCommitFiles(t *testing.T, expect []string, files []*api.CommitAffect
 
 func TestAPIReposGitCommits(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	// Login as User2.
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -52,7 +53,7 @@ func TestAPIReposGitCommits(t *testing.T) {
 
 func TestAPIReposGitCommitList(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	// Login as User2.
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -75,7 +76,7 @@ func TestAPIReposGitCommitList(t *testing.T) {
 
 func TestAPIReposGitCommitListPage2Empty(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	// Login as User2.
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -92,7 +93,7 @@ func TestAPIReposGitCommitListPage2Empty(t *testing.T) {
 
 func TestAPIReposGitCommitListDifferentBranch(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	// Login as User2.
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
diff --git a/integrations/api_repo_git_hook_test.go b/integrations/api_repo_git_hook_test.go
index f7e55d92a..490251b30 100644
--- a/integrations/api_repo_git_hook_test.go
+++ b/integrations/api_repo_git_hook_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -23,8 +24,8 @@ echo Hello, World!
 func TestAPIListGitHooks(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 37}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 37}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	// user1 is an admin user
 	session := loginUser(t, "user1")
@@ -49,8 +50,8 @@ func TestAPIListGitHooks(t *testing.T) {
 func TestAPIListGitHooksNoHooks(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	// user1 is an admin user
 	session := loginUser(t, "user1")
@@ -70,8 +71,8 @@ func TestAPIListGitHooksNoHooks(t *testing.T) {
 func TestAPIListGitHooksNoAccess(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, owner.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -83,8 +84,8 @@ func TestAPIListGitHooksNoAccess(t *testing.T) {
 func TestAPIGetGitHook(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 37}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 37}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	// user1 is an admin user
 	session := loginUser(t, "user1")
@@ -101,8 +102,8 @@ func TestAPIGetGitHook(t *testing.T) {
 func TestAPIGetGitHookNoAccess(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, owner.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -114,8 +115,8 @@ func TestAPIGetGitHookNoAccess(t *testing.T) {
 func TestAPIEditGitHook(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	// user1 is an admin user
 	session := loginUser(t, "user1")
@@ -144,8 +145,8 @@ func TestAPIEditGitHook(t *testing.T) {
 func TestAPIEditGitHookNoAccess(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, owner.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -160,8 +161,8 @@ func TestAPIEditGitHookNoAccess(t *testing.T) {
 func TestAPIDeleteGitHook(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 37}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 37}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	// user1 is an admin user
 	session := loginUser(t, "user1")
@@ -183,8 +184,8 @@ func TestAPIDeleteGitHook(t *testing.T) {
 func TestAPIDeleteGitHookNoAccess(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, owner.Name)
 	token := getTokenForLoggedInUser(t, session)
diff --git a/integrations/api_repo_git_notes_test.go b/integrations/api_repo_git_notes_test.go
index 6eae5e970..02235f9d9 100644
--- a/integrations/api_repo_git_notes_test.go
+++ b/integrations/api_repo_git_notes_test.go
@@ -10,13 +10,14 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestAPIReposGitNotes(t *testing.T) {
 	onGiteaRun(t, func(*testing.T, *url.URL) {
-		user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+		user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 		// Login as User2.
 		session := loginUser(t, user.Name)
 		token := getTokenForLoggedInUser(t, session)
diff --git a/integrations/api_repo_git_ref_test.go b/integrations/api_repo_git_ref_test.go
index 39237f59a..fcf5edc75 100644
--- a/integrations/api_repo_git_ref_test.go
+++ b/integrations/api_repo_git_ref_test.go
@@ -9,11 +9,12 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestAPIReposGitRefs(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	// Login as User2.
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
diff --git a/integrations/api_repo_git_tags_test.go b/integrations/api_repo_git_tags_test.go
index bf6fc7c85..01e0450c6 100644
--- a/integrations/api_repo_git_tags_test.go
+++ b/integrations/api_repo_git_tags_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/util"
@@ -19,8 +20,8 @@ import (
 
 func TestAPIGitTags(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 	// Login as User2.
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -64,8 +65,8 @@ func TestAPIGitTags(t *testing.T) {
 func TestAPIDeleteTagByName(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 	session := loginUser(t, owner.LowerName)
 	token := getTokenForLoggedInUser(t, session)
 
diff --git a/integrations/api_repo_git_trees_test.go b/integrations/api_repo_git_trees_test.go
index 6b4e120de..bf605d4d8 100644
--- a/integrations/api_repo_git_trees_test.go
+++ b/integrations/api_repo_git_trees_test.go
@@ -9,16 +9,17 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestAPIReposGitTrees(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)               // owner of the repo1 & repo16
-	user3 := models.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)               // owner of the repo3
-	user4 := models.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)               // owner of neither repos
-	repo1 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)   // public repo
-	repo3 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)   // public repo
-	repo16 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository) // private repo
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)               // owner of the repo1 & repo16
+	user3 := db.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)               // owner of the repo3
+	user4 := db.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)               // owner of neither repos
+	repo1 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)   // public repo
+	repo3 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)   // public repo
+	repo16 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository) // private repo
 	repo1TreeSHA := "65f1bf27bc3bf70f64657658635e66094edbcb4d"
 	repo3TreeSHA := "2a47ca4b614a9f5a43abbd5ad851a54a616ffee6"
 	repo16TreeSHA := "69554a64c1e6030f051e5c3f94bfbd773cd6a324"
diff --git a/integrations/api_repo_lfs_locks_test.go b/integrations/api_repo_lfs_locks_test.go
index 03549c11f..b2d8f0e63 100644
--- a/integrations/api_repo_lfs_locks_test.go
+++ b/integrations/api_repo_lfs_locks_test.go
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/lfs"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
@@ -21,8 +22,8 @@ import (
 func TestAPILFSLocksNotStarted(t *testing.T) {
 	defer prepareTestEnv(t)()
 	setting.LFS.StartServer = false
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 
 	req := NewRequestf(t, "GET", "/%s/%s.git/info/lfs/locks", user.Name, repo.Name)
 	MakeRequest(t, req, http.StatusNotFound)
@@ -37,8 +38,8 @@ func TestAPILFSLocksNotStarted(t *testing.T) {
 func TestAPILFSLocksNotLogin(t *testing.T) {
 	defer prepareTestEnv(t)()
 	setting.LFS.StartServer = true
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 
 	req := NewRequestf(t, "GET", "/%s/%s.git/info/lfs/locks", user.Name, repo.Name)
 	req.Header.Set("Accept", lfs.MediaType)
@@ -51,11 +52,11 @@ func TestAPILFSLocksNotLogin(t *testing.T) {
 func TestAPILFSLocksLogged(t *testing.T) {
 	defer prepareTestEnv(t)()
 	setting.LFS.StartServer = true
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User) //in org 3
-	user4 := models.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User) //in org 3
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User) //in org 3
+	user4 := db.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User) //in org 3
 
-	repo1 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	repo3 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository) // own by org 3
+	repo1 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	repo3 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository) // own by org 3
 
 	tests := []struct {
 		user       *models.User
diff --git a/integrations/api_repo_lfs_migrate_test.go b/integrations/api_repo_lfs_migrate_test.go
index 7280658b7..9acc96e4f 100644
--- a/integrations/api_repo_lfs_migrate_test.go
+++ b/integrations/api_repo_lfs_migrate_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/lfs"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
@@ -25,7 +26,7 @@ func TestAPIRepoLFSMigrateLocal(t *testing.T) {
 	setting.ImportLocalPaths = true
 	setting.Migrations.AllowLocalNetworks = true
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
 
diff --git a/integrations/api_repo_lfs_test.go b/integrations/api_repo_lfs_test.go
index 56a6fa81f..22c324f97 100644
--- a/integrations/api_repo_lfs_test.go
+++ b/integrations/api_repo_lfs_test.go
@@ -13,6 +13,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/json"
 	"code.gitea.io/gitea/modules/lfs"
 	"code.gitea.io/gitea/modules/setting"
@@ -25,8 +26,8 @@ func TestAPILFSNotStarted(t *testing.T) {
 
 	setting.LFS.StartServer = false
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 
 	req := NewRequestf(t, "POST", "/%s/%s.git/info/lfs/objects/batch", user.Name, repo.Name)
 	MakeRequest(t, req, http.StatusNotFound)
@@ -45,8 +46,8 @@ func TestAPILFSMediaType(t *testing.T) {
 
 	setting.LFS.StartServer = true
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 
 	req := NewRequestf(t, "POST", "/%s/%s.git/info/lfs/objects/batch", user.Name, repo.Name)
 	MakeRequest(t, req, http.StatusUnsupportedMediaType)
diff --git a/integrations/api_repo_raw_test.go b/integrations/api_repo_raw_test.go
index 62b734fa0..77b33473c 100644
--- a/integrations/api_repo_raw_test.go
+++ b/integrations/api_repo_raw_test.go
@@ -9,11 +9,12 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestAPIReposRaw(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	// Login as User2.
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
diff --git a/integrations/api_repo_tags_test.go b/integrations/api_repo_tags_test.go
index 0bf54d3a9..8897bc44b 100644
--- a/integrations/api_repo_tags_test.go
+++ b/integrations/api_repo_tags_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
 
@@ -18,7 +19,7 @@ import (
 
 func TestAPIRepoTags(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	// Login as User2.
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
diff --git a/integrations/api_repo_teams_test.go b/integrations/api_repo_teams_test.go
index 4a155130b..e718d79cb 100644
--- a/integrations/api_repo_teams_test.go
+++ b/integrations/api_repo_teams_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -19,9 +20,9 @@ func TestAPIRepoTeams(t *testing.T) {
 	defer prepareTestEnv(t)()
 
 	// publicOrgRepo = user3/repo21
-	publicOrgRepo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 32}).(*models.Repository)
+	publicOrgRepo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 32}).(*models.Repository)
 	// user4
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
 
@@ -61,7 +62,7 @@ func TestAPIRepoTeams(t *testing.T) {
 	res = session.MakeRequest(t, req, http.StatusForbidden)
 
 	// AddTeam with user2
-	user = models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user = db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	session = loginUser(t, user.Name)
 	token = getTokenForLoggedInUser(t, session)
 	url = fmt.Sprintf("/api/v1/repos/%s/teams/%s?token=%s", publicOrgRepo.FullName(), "team1", token)
diff --git a/integrations/api_repo_test.go b/integrations/api_repo_test.go
index 3948489f5..63da37382 100644
--- a/integrations/api_repo_test.go
+++ b/integrations/api_repo_test.go
@@ -12,6 +12,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/util"
@@ -21,15 +22,15 @@ import (
 
 func TestAPIUserReposNotLogin(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 
 	req := NewRequestf(t, "GET", "/api/v1/users/%s/repos", user.Name)
 	resp := MakeRequest(t, req, http.StatusOK)
 
 	var apiRepos []api.Repository
 	DecodeJSON(t, resp, &apiRepos)
-	expectedLen := models.GetCount(t, models.Repository{OwnerID: user.ID},
-		models.Cond("is_private = ?", false))
+	expectedLen := db.GetCount(t, models.Repository{OwnerID: user.ID},
+		db.Cond("is_private = ?", false))
 	assert.Len(t, apiRepos, expectedLen)
 	for _, repo := range apiRepos {
 		assert.EqualValues(t, user.ID, repo.Owner.ID)
@@ -52,11 +53,11 @@ func TestAPISearchRepo(t *testing.T) {
 		assert.False(t, repo.Private)
 	}
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 15}).(*models.User)
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 16}).(*models.User)
-	user3 := models.AssertExistsAndLoadBean(t, &models.User{ID: 18}).(*models.User)
-	user4 := models.AssertExistsAndLoadBean(t, &models.User{ID: 20}).(*models.User)
-	orgUser := models.AssertExistsAndLoadBean(t, &models.User{ID: 17}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 15}).(*models.User)
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 16}).(*models.User)
+	user3 := db.AssertExistsAndLoadBean(t, &models.User{ID: 18}).(*models.User)
+	user4 := db.AssertExistsAndLoadBean(t, &models.User{ID: 20}).(*models.User)
+	orgUser := db.AssertExistsAndLoadBean(t, &models.User{ID: 17}).(*models.User)
 
 	oldAPIDefaultNum := setting.API.DefaultPagingNum
 	defer func() {
@@ -208,7 +209,7 @@ var repoCache = make(map[int64]*models.Repository)
 
 func getRepo(t *testing.T, repoID int64) *models.Repository {
 	if _, ok := repoCache[repoID]; !ok {
-		repoCache[repoID] = models.AssertExistsAndLoadBean(t, &models.Repository{ID: repoID}).(*models.Repository)
+		repoCache[repoID] = db.AssertExistsAndLoadBean(t, &models.Repository{ID: repoID}).(*models.Repository)
 	}
 	return repoCache[repoID]
 }
@@ -245,11 +246,11 @@ func TestAPIViewRepo(t *testing.T) {
 
 func TestAPIOrgRepos(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
-	user3 := models.AssertExistsAndLoadBean(t, &models.User{ID: 5}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
+	user3 := db.AssertExistsAndLoadBean(t, &models.User{ID: 5}).(*models.User)
 	// User3 is an Org. Check their repos.
-	sourceOrg := models.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)
+	sourceOrg := db.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)
 
 	expectedResults := map[*models.User]struct {
 		count           int
@@ -291,7 +292,7 @@ func TestAPIOrgRepos(t *testing.T) {
 
 func TestAPIGetRepoByIDUnauthorized(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User)
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
 	req := NewRequestf(t, "GET", "/api/v1/repositories/2?token="+token)
@@ -315,7 +316,7 @@ func TestAPIRepoMigrate(t *testing.T) {
 
 	defer prepareTestEnv(t)()
 	for _, testCase := range testCases {
-		user := models.AssertExistsAndLoadBean(t, &models.User{ID: testCase.ctxUserID}).(*models.User)
+		user := db.AssertExistsAndLoadBean(t, &models.User{ID: testCase.ctxUserID}).(*models.User)
 		session := loginUser(t, user.Name)
 		token := getTokenForLoggedInUser(t, session)
 		req := NewRequestWithJSON(t, "POST", "/api/v1/repos/migrate?token="+token, &api.MigrateRepoOptions{
@@ -394,7 +395,7 @@ func TestAPIOrgRepoCreate(t *testing.T) {
 
 	defer prepareTestEnv(t)()
 	for _, testCase := range testCases {
-		user := models.AssertExistsAndLoadBean(t, &models.User{ID: testCase.ctxUserID}).(*models.User)
+		user := db.AssertExistsAndLoadBean(t, &models.User{ID: testCase.ctxUserID}).(*models.User)
 		session := loginUser(t, user.Name)
 		token := getTokenForLoggedInUser(t, session)
 		req := NewRequestWithJSON(t, "POST", fmt.Sprintf("/api/v1/org/%s/repos?token="+token, testCase.orgName), &api.CreateRepoOption{
@@ -462,7 +463,7 @@ func TestAPIRepoTransfer(t *testing.T) {
 	defer prepareTestEnv(t)()
 
 	//create repo to move
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
 	repoName := "moveME"
@@ -479,8 +480,8 @@ func TestAPIRepoTransfer(t *testing.T) {
 
 	//start testing
 	for _, testCase := range testCases {
-		user = models.AssertExistsAndLoadBean(t, &models.User{ID: testCase.ctxUserID}).(*models.User)
-		repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: apiRepo.ID}).(*models.Repository)
+		user = db.AssertExistsAndLoadBean(t, &models.User{ID: testCase.ctxUserID}).(*models.User)
+		repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: apiRepo.ID}).(*models.Repository)
 		session = loginUser(t, user.Name)
 		token = getTokenForLoggedInUser(t, session)
 		req = NewRequestWithJSON(t, "POST", fmt.Sprintf("/api/v1/repos/%s/%s/transfer?token=%s", repo.OwnerName, repo.Name, token), &api.TransferRepoOption{
@@ -491,18 +492,18 @@ func TestAPIRepoTransfer(t *testing.T) {
 	}
 
 	//cleanup
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: apiRepo.ID}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: apiRepo.ID}).(*models.Repository)
 	_ = models.DeleteRepository(user, repo.OwnerID, repo.ID)
 }
 
 func TestAPIGenerateRepo(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
 
-	templateRepo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 44}).(*models.Repository)
+	templateRepo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 44}).(*models.Repository)
 
 	// user
 	repo := new(api.Repository)
@@ -534,10 +535,10 @@ func TestAPIGenerateRepo(t *testing.T) {
 
 func TestAPIRepoGetReviewers(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 
 	req := NewRequestf(t, "GET", "/api/v1/repos/%s/%s/reviewers?token=%s", user.Name, repo.Name, token)
 	resp := session.MakeRequest(t, req, http.StatusOK)
@@ -548,10 +549,10 @@ func TestAPIRepoGetReviewers(t *testing.T) {
 
 func TestAPIRepoGetAssignees(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 
 	req := NewRequestf(t, "GET", "/api/v1/repos/%s/%s/assignees?token=%s", user.Name, repo.Name, token)
 	resp := session.MakeRequest(t, req, http.StatusOK)
diff --git a/integrations/api_repo_topic_test.go b/integrations/api_repo_topic_test.go
index bab17a68b..cc76f1885 100644
--- a/integrations/api_repo_topic_test.go
+++ b/integrations/api_repo_topic_test.go
@@ -11,6 +11,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -50,11 +51,11 @@ func TestAPITopicSearch(t *testing.T) {
 
 func TestAPIRepoTopic(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User) // owner of repo2
-	user3 := models.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User) // owner of repo3
-	user4 := models.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User) // write access to repo 3
-	repo2 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 2}).(*models.Repository)
-	repo3 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User) // owner of repo2
+	user3 := db.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User) // owner of repo3
+	user4 := db.AssertExistsAndLoadBean(t, &models.User{ID: 4}).(*models.User) // write access to repo 3
+	repo2 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 2}).(*models.Repository)
+	repo3 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)
 
 	// Get user2's token
 	session := loginUser(t, user2.Name)
diff --git a/integrations/api_team_test.go b/integrations/api_team_test.go
index 0b77dc3be..086450033 100644
--- a/integrations/api_team_test.go
+++ b/integrations/api_team_test.go
@@ -11,6 +11,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/convert"
 	api "code.gitea.io/gitea/modules/structs"
 
@@ -20,9 +21,9 @@ import (
 func TestAPITeam(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	teamUser := models.AssertExistsAndLoadBean(t, &models.TeamUser{}).(*models.TeamUser)
-	team := models.AssertExistsAndLoadBean(t, &models.Team{ID: teamUser.TeamID}).(*models.Team)
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: teamUser.UID}).(*models.User)
+	teamUser := db.AssertExistsAndLoadBean(t, &models.TeamUser{}).(*models.TeamUser)
+	team := db.AssertExistsAndLoadBean(t, &models.Team{ID: teamUser.TeamID}).(*models.Team)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: teamUser.UID}).(*models.User)
 
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session)
@@ -35,8 +36,8 @@ func TestAPITeam(t *testing.T) {
 	assert.Equal(t, team.Name, apiTeam.Name)
 
 	// non team member user will not access the teams details
-	teamUser2 := models.AssertExistsAndLoadBean(t, &models.TeamUser{ID: 3}).(*models.TeamUser)
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: teamUser2.UID}).(*models.User)
+	teamUser2 := db.AssertExistsAndLoadBean(t, &models.TeamUser{ID: 3}).(*models.TeamUser)
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: teamUser2.UID}).(*models.User)
 
 	session = loginUser(t, user2.Name)
 	token = getTokenForLoggedInUser(t, session)
@@ -47,11 +48,11 @@ func TestAPITeam(t *testing.T) {
 	_ = session.MakeRequest(t, req, http.StatusUnauthorized)
 
 	// Get an admin user able to create, update and delete teams.
-	user = models.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
+	user = db.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
 	session = loginUser(t, user.Name)
 	token = getTokenForLoggedInUser(t, session)
 
-	org := models.AssertExistsAndLoadBean(t, &models.User{ID: 6}).(*models.User)
+	org := db.AssertExistsAndLoadBean(t, &models.User{ID: 6}).(*models.User)
 
 	// Create team.
 	teamToCreate := &api.CreateTeamOption{
@@ -101,7 +102,7 @@ func TestAPITeam(t *testing.T) {
 		teamToEdit.Permission, teamToEdit.Units)
 
 	// Read team.
-	teamRead := models.AssertExistsAndLoadBean(t, &models.Team{ID: teamID}).(*models.Team)
+	teamRead := db.AssertExistsAndLoadBean(t, &models.Team{ID: teamID}).(*models.Team)
 	req = NewRequestf(t, "GET", "/api/v1/teams/%d?token="+token, teamID)
 	resp = session.MakeRequest(t, req, http.StatusOK)
 	DecodeJSON(t, resp, &apiTeam)
@@ -111,7 +112,7 @@ func TestAPITeam(t *testing.T) {
 	// Delete team.
 	req = NewRequestf(t, "DELETE", "/api/v1/teams/%d?token="+token, teamID)
 	session.MakeRequest(t, req, http.StatusNoContent)
-	models.AssertNotExistsBean(t, &models.Team{ID: teamID})
+	db.AssertNotExistsBean(t, &models.Team{ID: teamID})
 }
 
 func checkTeamResponse(t *testing.T, apiTeam *api.Team, name, description string, includesAllRepositories bool, permission string, units []string) {
@@ -125,7 +126,7 @@ func checkTeamResponse(t *testing.T, apiTeam *api.Team, name, description string
 }
 
 func checkTeamBean(t *testing.T, id int64, name, description string, includesAllRepositories bool, permission string, units []string) {
-	team := models.AssertExistsAndLoadBean(t, &models.Team{ID: id}).(*models.Team)
+	team := db.AssertExistsAndLoadBean(t, &models.Team{ID: id}).(*models.Team)
 	assert.NoError(t, team.GetUnits(), "GetUnits")
 	checkTeamResponse(t, convert.ToTeam(team), name, description, includesAllRepositories, permission, units)
 }
@@ -138,8 +139,8 @@ type TeamSearchResults struct {
 func TestAPITeamSearch(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	org := models.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	org := db.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)
 
 	var results TeamSearchResults
 
@@ -154,7 +155,7 @@ func TestAPITeamSearch(t *testing.T) {
 	assert.Equal(t, "test_team", results.Data[0].Name)
 
 	// no access if not organization member
-	user5 := models.AssertExistsAndLoadBean(t, &models.User{ID: 5}).(*models.User)
+	user5 := db.AssertExistsAndLoadBean(t, &models.User{ID: 5}).(*models.User)
 	session = loginUser(t, user5.Name)
 	csrf = GetCSRF(t, session, "/"+org.Name)
 	req = NewRequestf(t, "GET", "/api/v1/orgs/%s/teams/search?q=%s", org.Name, "team")
diff --git a/integrations/api_team_user_test.go b/integrations/api_team_user_test.go
index 5a8fba512..747227269 100644
--- a/integrations/api_team_user_test.go
+++ b/integrations/api_team_user_test.go
@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/convert"
 	api "code.gitea.io/gitea/modules/structs"
 	"github.com/stretchr/testify/assert"
@@ -29,7 +30,7 @@ func TestAPITeamUser(t *testing.T) {
 	var user2 *api.User
 	DecodeJSON(t, resp, &user2)
 	user2.Created = user2.Created.In(time.Local)
-	user := models.AssertExistsAndLoadBean(t, &models.User{Name: "user2"}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{Name: "user2"}).(*models.User)
 
 	expectedUser := convert.ToUser(user, user)
 
diff --git a/integrations/api_token_test.go b/integrations/api_token_test.go
index 464b7ba38..1a6d53547 100644
--- a/integrations/api_token_test.go
+++ b/integrations/api_token_test.go
@@ -9,13 +9,14 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 )
 
 // TestAPICreateAndDeleteToken tests that token that was just created can be deleted
 func TestAPICreateAndDeleteToken(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
 
 	req := NewRequestWithJSON(t, "POST", "/api/v1/users/user1/tokens", map[string]string{
 		"name": "test-key-1",
@@ -25,7 +26,7 @@ func TestAPICreateAndDeleteToken(t *testing.T) {
 
 	var newAccessToken api.AccessToken
 	DecodeJSON(t, resp, &newAccessToken)
-	models.AssertExistsAndLoadBean(t, &models.AccessToken{
+	db.AssertExistsAndLoadBean(t, &models.AccessToken{
 		ID:    newAccessToken.ID,
 		Name:  newAccessToken.Name,
 		Token: newAccessToken.Token,
@@ -36,7 +37,7 @@ func TestAPICreateAndDeleteToken(t *testing.T) {
 	req = AddBasicAuthHeader(req, user.Name)
 	MakeRequest(t, req, http.StatusNoContent)
 
-	models.AssertNotExistsBean(t, &models.AccessToken{ID: newAccessToken.ID})
+	db.AssertNotExistsBean(t, &models.AccessToken{ID: newAccessToken.ID})
 
 	req = NewRequestWithJSON(t, "POST", "/api/v1/users/user1/tokens", map[string]string{
 		"name": "test-key-2",
@@ -49,15 +50,15 @@ func TestAPICreateAndDeleteToken(t *testing.T) {
 	req = AddBasicAuthHeader(req, user.Name)
 	MakeRequest(t, req, http.StatusNoContent)
 
-	models.AssertNotExistsBean(t, &models.AccessToken{ID: newAccessToken.ID})
+	db.AssertNotExistsBean(t, &models.AccessToken{ID: newAccessToken.ID})
 }
 
 // TestAPIDeleteMissingToken ensures that error is thrown when token not found
 func TestAPIDeleteMissingToken(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
 
-	req := NewRequestf(t, "DELETE", "/api/v1/users/user1/tokens/%d", models.NonexistentID)
+	req := NewRequestf(t, "DELETE", "/api/v1/users/user1/tokens/%d", db.NonexistentID)
 	req = AddBasicAuthHeader(req, user.Name)
 	MakeRequest(t, req, http.StatusNotFound)
 }
diff --git a/integrations/api_user_orgs_test.go b/integrations/api_user_orgs_test.go
index c72ee7609..36b11335c 100644
--- a/integrations/api_user_orgs_test.go
+++ b/integrations/api_user_orgs_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -24,7 +25,7 @@ func TestUserOrgs(t *testing.T) {
 
 	orgs := getUserOrgs(t, adminUsername, normalUsername)
 
-	user3 := models.AssertExistsAndLoadBean(t, &models.User{Name: "user3"}).(*models.User)
+	user3 := db.AssertExistsAndLoadBean(t, &models.User{Name: "user3"}).(*models.User)
 
 	assert.Equal(t, []*api.Organization{
 		{
@@ -80,7 +81,7 @@ func TestMyOrgs(t *testing.T) {
 	resp = session.MakeRequest(t, req, http.StatusOK)
 	var orgs []*api.Organization
 	DecodeJSON(t, resp, &orgs)
-	user3 := models.AssertExistsAndLoadBean(t, &models.User{Name: "user3"}).(*models.User)
+	user3 := db.AssertExistsAndLoadBean(t, &models.User{Name: "user3"}).(*models.User)
 
 	assert.Equal(t, []*api.Organization{
 		{
diff --git a/integrations/api_user_search_test.go b/integrations/api_user_search_test.go
index f7349827e..d6144d9e8 100644
--- a/integrations/api_user_search_test.go
+++ b/integrations/api_user_search_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
 
@@ -51,7 +52,7 @@ func TestAPIUserSearchNotLoggedIn(t *testing.T) {
 	var modelUser *models.User
 	for _, user := range results.Data {
 		assert.Contains(t, user.UserName, query)
-		modelUser = models.AssertExistsAndLoadBean(t, &models.User{ID: user.ID}).(*models.User)
+		modelUser = db.AssertExistsAndLoadBean(t, &models.User{ID: user.ID}).(*models.User)
 		if modelUser.KeepEmailPrivate {
 			assert.EqualValues(t, fmt.Sprintf("%s@%s", modelUser.LowerName, setting.Service.NoReplyAddress), user.Email)
 		} else {
diff --git a/integrations/benchmarks_test.go b/integrations/benchmarks_test.go
index 841ecbf7e..5df0d7b74 100644
--- a/integrations/benchmarks_test.go
+++ b/integrations/benchmarks_test.go
@@ -11,6 +11,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 )
 
@@ -32,7 +33,7 @@ func BenchmarkRepoBranchCommit(b *testing.B) {
 
 		for _, repoID := range samples {
 			b.StopTimer()
-			repo := models.AssertExistsAndLoadBean(b, &models.Repository{ID: repoID}).(*models.Repository)
+			repo := db.AssertExistsAndLoadBean(b, &models.Repository{ID: repoID}).(*models.Repository)
 			b.StartTimer()
 			b.Run(repo.Name, func(b *testing.B) {
 				session := loginUser(b, "user2")
diff --git a/integrations/change_default_branch_test.go b/integrations/change_default_branch_test.go
index dcd6d9b08..d6a666435 100644
--- a/integrations/change_default_branch_test.go
+++ b/integrations/change_default_branch_test.go
@@ -10,12 +10,13 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestChangeDefaultBranch(t *testing.T) {
 	defer prepareTestEnv(t)()
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	session := loginUser(t, owner.Name)
 	branchesURL := fmt.Sprintf("/%s/%s/settings/branches", owner.Name, repo.Name)
diff --git a/integrations/delete_user_test.go b/integrations/delete_user_test.go
index 86be6f22a..f529734e1 100644
--- a/integrations/delete_user_test.go
+++ b/integrations/delete_user_test.go
@@ -10,18 +10,19 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func assertUserDeleted(t *testing.T, userID int64) {
-	models.AssertNotExistsBean(t, &models.User{ID: userID})
-	models.AssertNotExistsBean(t, &models.Follow{UserID: userID})
-	models.AssertNotExistsBean(t, &models.Follow{FollowID: userID})
-	models.AssertNotExistsBean(t, &models.Repository{OwnerID: userID})
-	models.AssertNotExistsBean(t, &models.Access{UserID: userID})
-	models.AssertNotExistsBean(t, &models.OrgUser{UID: userID})
-	models.AssertNotExistsBean(t, &models.IssueUser{UID: userID})
-	models.AssertNotExistsBean(t, &models.TeamUser{UID: userID})
-	models.AssertNotExistsBean(t, &models.Star{UID: userID})
+	db.AssertNotExistsBean(t, &models.User{ID: userID})
+	db.AssertNotExistsBean(t, &models.Follow{UserID: userID})
+	db.AssertNotExistsBean(t, &models.Follow{FollowID: userID})
+	db.AssertNotExistsBean(t, &models.Repository{OwnerID: userID})
+	db.AssertNotExistsBean(t, &models.Access{UserID: userID})
+	db.AssertNotExistsBean(t, &models.OrgUser{UID: userID})
+	db.AssertNotExistsBean(t, &models.IssueUser{UID: userID})
+	db.AssertNotExistsBean(t, &models.TeamUser{UID: userID})
+	db.AssertNotExistsBean(t, &models.Star{UID: userID})
 }
 
 func TestUserDeleteAccount(t *testing.T) {
@@ -51,5 +52,5 @@ func TestUserDeleteAccountStillOwnRepos(t *testing.T) {
 	session.MakeRequest(t, req, http.StatusFound)
 
 	// user should not have been deleted, because the user still owns repos
-	models.AssertExistsAndLoadBean(t, &models.User{ID: 2})
+	db.AssertExistsAndLoadBean(t, &models.User{ID: 2})
 }
diff --git a/integrations/empty_repo_test.go b/integrations/empty_repo_test.go
index 77b8adf68..7346c34b2 100644
--- a/integrations/empty_repo_test.go
+++ b/integrations/empty_repo_test.go
@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestEmptyRepo(t *testing.T) {
@@ -19,8 +20,8 @@ func TestEmptyRepo(t *testing.T) {
 		"commit/1ae57b34ccf7e18373",
 		"graph",
 	}
-	emptyRepo := models.AssertExistsAndLoadBean(t, &models.Repository{}, models.Cond("is_empty = ?", true)).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: emptyRepo.OwnerID}).(*models.User)
+	emptyRepo := db.AssertExistsAndLoadBean(t, &models.Repository{}, db.Cond("is_empty = ?", true)).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: emptyRepo.OwnerID}).(*models.User)
 	for _, subpath := range subpaths {
 		req := NewRequestf(t, "GET", "/%s/%s/%s", owner.Name, emptyRepo.Name, subpath)
 		MakeRequest(t, req, http.StatusNotFound)
diff --git a/integrations/eventsource_test.go b/integrations/eventsource_test.go
index caaf8c2ce..17c5ff8ab 100644
--- a/integrations/eventsource_test.go
+++ b/integrations/eventsource_test.go
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/eventsource"
 	api "code.gitea.io/gitea/modules/structs"
 	"github.com/stretchr/testify/assert"
@@ -49,9 +50,9 @@ func TestEventSourceManagerRun(t *testing.T) {
 		}
 	}
 
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	repo1 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	thread5 := models.AssertExistsAndLoadBean(t, &models.Notification{ID: 5}).(*models.Notification)
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo1 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	thread5 := db.AssertExistsAndLoadBean(t, &models.Notification{ID: 5}).(*models.Notification)
 	assert.NoError(t, thread5.LoadAttributes())
 	session := loginUser(t, user2.Name)
 	token := getTokenForLoggedInUser(t, session)
diff --git a/integrations/git_test.go b/integrations/git_test.go
index caafd1122..72e01d375 100644
--- a/integrations/git_test.go
+++ b/integrations/git_test.go
@@ -18,6 +18,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/lfs"
 	"code.gitea.io/gitea/modules/setting"
@@ -630,7 +631,7 @@ func doCreateAgitFlowPull(dstPath string, ctx *APITestContext, baseBranch, headB
 			return
 		}
 
-		pullNum := models.GetCount(t, &models.PullRequest{})
+		pullNum := db.GetCount(t, &models.PullRequest{})
 
 		t.Run("CreateHeadBranch", doGitCreateBranch(dstPath, headBranch))
 
@@ -666,8 +667,8 @@ func doCreateAgitFlowPull(dstPath string, ctx *APITestContext, baseBranch, headB
 			if !assert.NoError(t, err) {
 				return
 			}
-			models.AssertCount(t, &models.PullRequest{}, pullNum+1)
-			pr1 = models.AssertExistsAndLoadBean(t, &models.PullRequest{
+			db.AssertCount(t, &models.PullRequest{}, pullNum+1)
+			pr1 = db.AssertExistsAndLoadBean(t, &models.PullRequest{
 				HeadRepoID: repo.ID,
 				Flow:       models.PullRequestFlowAGit,
 			}).(*models.PullRequest)
@@ -687,8 +688,8 @@ func doCreateAgitFlowPull(dstPath string, ctx *APITestContext, baseBranch, headB
 			if !assert.NoError(t, err) {
 				return
 			}
-			models.AssertCount(t, &models.PullRequest{}, pullNum+2)
-			pr2 = models.AssertExistsAndLoadBean(t, &models.PullRequest{
+			db.AssertCount(t, &models.PullRequest{}, pullNum+2)
+			pr2 = db.AssertExistsAndLoadBean(t, &models.PullRequest{
 				HeadRepoID: repo.ID,
 				Index:      pr1.Index + 1,
 				Flow:       models.PullRequestFlowAGit,
@@ -740,7 +741,7 @@ func doCreateAgitFlowPull(dstPath string, ctx *APITestContext, baseBranch, headB
 			if !assert.NoError(t, err) {
 				return
 			}
-			models.AssertCount(t, &models.PullRequest{}, pullNum+2)
+			db.AssertCount(t, &models.PullRequest{}, pullNum+2)
 			prMsg, err := doAPIGetPullRequest(*ctx, ctx.Username, ctx.Reponame, pr1.Index)(t)
 			if !assert.NoError(t, err) {
 				return
@@ -752,7 +753,7 @@ func doCreateAgitFlowPull(dstPath string, ctx *APITestContext, baseBranch, headB
 			if !assert.NoError(t, err) {
 				return
 			}
-			models.AssertCount(t, &models.PullRequest{}, pullNum+2)
+			db.AssertCount(t, &models.PullRequest{}, pullNum+2)
 			prMsg, err = doAPIGetPullRequest(*ctx, ctx.Username, ctx.Reponame, pr2.Index)(t)
 			if !assert.NoError(t, err) {
 				return
diff --git a/integrations/gpg_git_test.go b/integrations/gpg_git_test.go
index 8c78faf7d..11d9a0e2a 100644
--- a/integrations/gpg_git_test.go
+++ b/integrations/gpg_git_test.go
@@ -13,6 +13,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/process"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
@@ -60,7 +61,7 @@ func TestGPGGit(t *testing.T) {
 	setting.Repository.Signing.SigningKey = rootKeyID
 	setting.Repository.Signing.SigningName = "gitea"
 	setting.Repository.Signing.SigningEmail = "gitea@fake.local"
-	user := models.AssertExistsAndLoadBean(t, &models.User{Name: username}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{Name: username}).(*models.User)
 
 	setting.Repository.Signing.InitialCommit = []string{"never"}
 	setting.Repository.Signing.CRUDActions = []string{"never"}
diff --git a/integrations/integration_test.go b/integrations/integration_test.go
index 1003f136d..fac36320c 100644
--- a/integrations/integration_test.go
+++ b/integrations/integration_test.go
@@ -25,6 +25,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/graceful"
@@ -111,7 +112,7 @@ func TestMain(m *testing.M) {
 		}
 	}
 
-	err := models.InitFixtures(
+	err := db.InitFixtures(
 		path.Join(filepath.Dir(setting.AppPath), "models/fixtures/"),
 	)
 	if err != nil {
@@ -247,7 +248,7 @@ func prepareTestEnv(t testing.TB, skip ...int) func() {
 		ourSkip += skip[0]
 	}
 	deferFn := PrintCurrentTest(t, ourSkip)
-	assert.NoError(t, models.LoadFixtures())
+	assert.NoError(t, db.LoadFixtures())
 	assert.NoError(t, util.RemoveAll(setting.RepoRootPath))
 
 	assert.NoError(t, util.CopyDir(path.Join(filepath.Dir(setting.AppPath), "integrations/gitea-repositories-meta"), setting.RepoRootPath))
@@ -524,7 +525,7 @@ func GetCSRF(t testing.TB, session *TestSession, urlStr string) string {
 // within a single test this is required
 func resetFixtures(t *testing.T) {
 	assert.NoError(t, queue.GetManager().FlushAll(context.Background(), -1))
-	assert.NoError(t, models.LoadFixtures())
+	assert.NoError(t, db.LoadFixtures())
 	assert.NoError(t, util.RemoveAll(setting.RepoRootPath))
 	assert.NoError(t, util.CopyDir(path.Join(filepath.Dir(setting.AppPath), "integrations/gitea-repositories-meta"), setting.RepoRootPath))
 }
diff --git a/integrations/issue_test.go b/integrations/issue_test.go
index 9b1447bd8..132f0822a 100644
--- a/integrations/issue_test.go
+++ b/integrations/issue_test.go
@@ -14,6 +14,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/indexer/issues"
 	"code.gitea.io/gitea/modules/references"
 	"code.gitea.io/gitea/modules/setting"
@@ -35,7 +36,7 @@ func getIssue(t *testing.T, repoID int64, issueSelection *goquery.Selection) *mo
 	indexStr := href[strings.LastIndexByte(href, '/')+1:]
 	index, err := strconv.Atoi(indexStr)
 	assert.NoError(t, err, "Invalid issue href: %s", href)
-	return models.AssertExistsAndLoadBean(t, &models.Issue{RepoID: repoID, Index: int64(index)}).(*models.Issue)
+	return db.AssertExistsAndLoadBean(t, &models.Issue{RepoID: repoID, Index: int64(index)}).(*models.Issue)
 }
 
 func assertMatch(t testing.TB, issue *models.Issue, keyword string) {
@@ -60,8 +61,8 @@ func TestNoLoginViewIssues(t *testing.T) {
 func TestViewIssuesSortByType(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 
 	session := loginUser(t, user.Name)
 	req := NewRequest(t, "GET", repo.RelLink()+"/issues?type=created_by")
@@ -69,10 +70,10 @@ func TestViewIssuesSortByType(t *testing.T) {
 
 	htmlDoc := NewHTMLParser(t, resp.Body)
 	issuesSelection := getIssuesSelection(t, htmlDoc)
-	expectedNumIssues := models.GetCount(t,
+	expectedNumIssues := db.GetCount(t,
 		&models.Issue{RepoID: repo.ID, PosterID: user.ID},
-		models.Cond("is_closed=?", false),
-		models.Cond("is_pull=?", false),
+		db.Cond("is_closed=?", false),
+		db.Cond("is_pull=?", false),
 	)
 	if expectedNumIssues > setting.UI.IssuePagingNum {
 		expectedNumIssues = setting.UI.IssuePagingNum
@@ -88,8 +89,8 @@ func TestViewIssuesSortByType(t *testing.T) {
 func TestViewIssuesKeyword(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	issue := models.AssertExistsAndLoadBean(t, &models.Issue{
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	issue := db.AssertExistsAndLoadBean(t, &models.Issue{
 		RepoID: repo.ID,
 		Index:  1,
 	}).(*models.Issue)
@@ -235,7 +236,7 @@ func TestIssueCrossReference(t *testing.T) {
 
 	// Ref from issue title
 	issueRefURL, issueRef := testIssueWithBean(t, "user2", 1, fmt.Sprintf("Title ref #%d", issueBase.Index), "Description")
-	models.AssertExistsAndLoadBean(t, &models.Comment{
+	db.AssertExistsAndLoadBean(t, &models.Comment{
 		IssueID:      issueBase.ID,
 		RefRepoID:    1,
 		RefIssueID:   issueRef.ID,
@@ -245,7 +246,7 @@ func TestIssueCrossReference(t *testing.T) {
 
 	// Edit title, neuter ref
 	testIssueChangeInfo(t, "user2", issueRefURL, "title", "Title no ref")
-	models.AssertExistsAndLoadBean(t, &models.Comment{
+	db.AssertExistsAndLoadBean(t, &models.Comment{
 		IssueID:      issueBase.ID,
 		RefRepoID:    1,
 		RefIssueID:   issueRef.ID,
@@ -255,7 +256,7 @@ func TestIssueCrossReference(t *testing.T) {
 
 	// Ref from issue content
 	issueRefURL, issueRef = testIssueWithBean(t, "user2", 1, "TitleXRef", fmt.Sprintf("Description ref #%d", issueBase.Index))
-	models.AssertExistsAndLoadBean(t, &models.Comment{
+	db.AssertExistsAndLoadBean(t, &models.Comment{
 		IssueID:      issueBase.ID,
 		RefRepoID:    1,
 		RefIssueID:   issueRef.ID,
@@ -265,7 +266,7 @@ func TestIssueCrossReference(t *testing.T) {
 
 	// Edit content, neuter ref
 	testIssueChangeInfo(t, "user2", issueRefURL, "content", "Description no ref")
-	models.AssertExistsAndLoadBean(t, &models.Comment{
+	db.AssertExistsAndLoadBean(t, &models.Comment{
 		IssueID:      issueBase.ID,
 		RefRepoID:    1,
 		RefIssueID:   issueRef.ID,
@@ -283,11 +284,11 @@ func TestIssueCrossReference(t *testing.T) {
 		RefCommentID: commentID,
 		RefIsPull:    false,
 		RefAction:    references.XRefActionNone}
-	models.AssertExistsAndLoadBean(t, comment)
+	db.AssertExistsAndLoadBean(t, comment)
 
 	// Ref from a different repository
 	issueRefURL, issueRef = testIssueWithBean(t, "user12", 10, "TitleXRef", fmt.Sprintf("Description ref user2/repo1#%d", issueBase.Index))
-	models.AssertExistsAndLoadBean(t, &models.Comment{
+	db.AssertExistsAndLoadBean(t, &models.Comment{
 		IssueID:      issueBase.ID,
 		RefRepoID:    10,
 		RefIssueID:   issueRef.ID,
@@ -303,7 +304,7 @@ func testIssueWithBean(t *testing.T, user string, repoID int64, title, content s
 	index, err := strconv.Atoi(indexStr)
 	assert.NoError(t, err, "Invalid issue href: %s", issueURL)
 	issue := &models.Issue{RepoID: repoID, Index: int64(index)}
-	models.AssertExistsAndLoadBean(t, issue)
+	db.AssertExistsAndLoadBean(t, issue)
 	return issueURL, issue
 }
 
diff --git a/integrations/migrate_test.go b/integrations/migrate_test.go
index b0395fbc3..e79be238d 100644
--- a/integrations/migrate_test.go
+++ b/integrations/migrate_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/migrations"
 	"code.gitea.io/gitea/modules/setting"
 
@@ -17,9 +18,9 @@ import (
 )
 
 func TestMigrateLocalPath(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	adminUser := models.AssertExistsAndLoadBean(t, &models.User{Name: "user1"}).(*models.User)
+	adminUser := db.AssertExistsAndLoadBean(t, &models.User{Name: "user1"}).(*models.User)
 
 	old := setting.ImportLocalPaths
 	setting.ImportLocalPaths = true
diff --git a/integrations/migration-test/migration_test.go b/integrations/migration-test/migration_test.go
index 209ff5a05..66aca0ef7 100644
--- a/integrations/migration-test/migration_test.go
+++ b/integrations/migration-test/migration_test.go
@@ -19,7 +19,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/integrations"
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/models/migrations"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/charset"
@@ -256,13 +256,13 @@ func doMigrationTest(t *testing.T, version string) {
 
 	setting.NewXORMLogService(false)
 
-	err := models.NewEngine(context.Background(), wrappedMigrate)
+	err := db.NewEngine(context.Background(), wrappedMigrate)
 	assert.NoError(t, err)
 	currentEngine.Close()
 
-	beans, _ := models.NamesToBean()
+	beans, _ := db.NamesToBean()
 
-	err = models.NewEngine(context.Background(), func(x *xorm.Engine) error {
+	err = db.NewEngine(context.Background(), func(x *xorm.Engine) error {
 		currentEngine = x
 		return migrations.RecreateTables(beans...)(x)
 	})
@@ -270,7 +270,7 @@ func doMigrationTest(t *testing.T, version string) {
 	currentEngine.Close()
 
 	// We do this a second time to ensure that there is not a problem with retained indices
-	err = models.NewEngine(context.Background(), func(x *xorm.Engine) error {
+	err = db.NewEngine(context.Background(), func(x *xorm.Engine) error {
 		currentEngine = x
 		return migrations.RecreateTables(beans...)(x)
 	})
diff --git a/integrations/mirror_pull_test.go b/integrations/mirror_pull_test.go
index 3908f3555..f396aac4b 100644
--- a/integrations/mirror_pull_test.go
+++ b/integrations/mirror_pull_test.go
@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	migration "code.gitea.io/gitea/modules/migrations/base"
 	"code.gitea.io/gitea/modules/repository"
@@ -21,8 +22,8 @@ import (
 func TestMirrorPull(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 	repoPath := models.RepoPath(user.Name, repo.Name)
 
 	opts := migration.MigrateOptions{
diff --git a/integrations/mirror_push_test.go b/integrations/mirror_push_test.go
index 3191ef770..3d2966cfd 100644
--- a/integrations/mirror_push_test.go
+++ b/integrations/mirror_push_test.go
@@ -12,6 +12,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/repository"
 	"code.gitea.io/gitea/modules/setting"
@@ -29,8 +30,8 @@ func testMirrorPush(t *testing.T, u *url.URL) {
 
 	setting.Migrations.AllowLocalNetworks = true
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	srcRepo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	srcRepo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 
 	mirrorRepo, err := repository.CreateRepository(user, user, models.CreateRepoOptions{
 		Name: "test-push-mirror",
diff --git a/integrations/org_count_test.go b/integrations/org_count_test.go
index 20917dc17..bd64139b2 100644
--- a/integrations/org_count_test.go
+++ b/integrations/org_count_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 	"github.com/stretchr/testify/assert"
 )
@@ -110,7 +111,7 @@ func doCheckOrgCounts(username string, orgCounts map[string]int, strict bool, ca
 	}
 
 	return func(t *testing.T) {
-		user := models.AssertExistsAndLoadBean(t, &models.User{
+		user := db.AssertExistsAndLoadBean(t, &models.User{
 			Name: username,
 		}).(*models.User)
 
diff --git a/integrations/privateactivity_test.go b/integrations/privateactivity_test.go
index 23c6a7e8c..e7b618abd 100644
--- a/integrations/privateactivity_test.go
+++ b/integrations/privateactivity_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -24,8 +25,8 @@ const privateActivityTestOtherUser = "user4"
 // activity helpers
 
 func testPrivateActivityDoSomethingForActionEntries(t *testing.T) {
-	repoBefore := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repoBefore.OwnerID}).(*models.User)
+	repoBefore := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repoBefore.OwnerID}).(*models.User)
 
 	session := loginUser(t, privateActivityTestUser)
 	token := getTokenForLoggedInUser(t, session)
diff --git a/integrations/pull_merge_test.go b/integrations/pull_merge_test.go
index b4a3397a4..867817c2c 100644
--- a/integrations/pull_merge_test.go
+++ b/integrations/pull_merge_test.go
@@ -17,6 +17,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/test"
@@ -219,15 +220,15 @@ func TestCantMergeConflict(t *testing.T) {
 		session.MakeRequest(t, req, 201)
 
 		// Now this PR will be marked conflict - or at least a race will do - so drop down to pure code at this point...
-		user1 := models.AssertExistsAndLoadBean(t, &models.User{
+		user1 := db.AssertExistsAndLoadBean(t, &models.User{
 			Name: "user1",
 		}).(*models.User)
-		repo1 := models.AssertExistsAndLoadBean(t, &models.Repository{
+		repo1 := db.AssertExistsAndLoadBean(t, &models.Repository{
 			OwnerID: user1.ID,
 			Name:    "repo1",
 		}).(*models.Repository)
 
-		pr := models.AssertExistsAndLoadBean(t, &models.PullRequest{
+		pr := db.AssertExistsAndLoadBean(t, &models.PullRequest{
 			HeadRepoID: repo1.ID,
 			BaseRepoID: repo1.ID,
 			HeadBranch: "conflict",
@@ -256,10 +257,10 @@ func TestCantMergeUnrelated(t *testing.T) {
 
 		// Now we want to create a commit on a branch that is totally unrelated to our current head
 		// Drop down to pure code at this point
-		user1 := models.AssertExistsAndLoadBean(t, &models.User{
+		user1 := db.AssertExistsAndLoadBean(t, &models.User{
 			Name: "user1",
 		}).(*models.User)
-		repo1 := models.AssertExistsAndLoadBean(t, &models.Repository{
+		repo1 := db.AssertExistsAndLoadBean(t, &models.Repository{
 			OwnerID: user1.ID,
 			Name:    "repo1",
 		}).(*models.Repository)
@@ -318,7 +319,7 @@ func TestCantMergeUnrelated(t *testing.T) {
 		// Now this PR could be marked conflict - or at least a race may occur - so drop down to pure code at this point...
 		gitRepo, err := git.OpenRepository(path)
 		assert.NoError(t, err)
-		pr := models.AssertExistsAndLoadBean(t, &models.PullRequest{
+		pr := db.AssertExistsAndLoadBean(t, &models.PullRequest{
 			HeadRepoID: repo1.ID,
 			BaseRepoID: repo1.ID,
 			HeadBranch: "unrelated",
diff --git a/integrations/pull_update_test.go b/integrations/pull_update_test.go
index 3e3b987b6..ea3a4794a 100644
--- a/integrations/pull_update_test.go
+++ b/integrations/pull_update_test.go
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/repofiles"
 	repo_module "code.gitea.io/gitea/modules/repository"
 	pull_service "code.gitea.io/gitea/services/pull"
@@ -22,8 +23,8 @@ import (
 func TestAPIPullUpdate(t *testing.T) {
 	onGiteaRun(t, func(t *testing.T, giteaURL *url.URL) {
 		//Create PR to test
-		user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-		org26 := models.AssertExistsAndLoadBean(t, &models.User{ID: 26}).(*models.User)
+		user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+		org26 := db.AssertExistsAndLoadBean(t, &models.User{ID: 26}).(*models.User)
 		pr := createOutdatedPR(t, user, org26)
 
 		//Test GetDiverging
@@ -50,8 +51,8 @@ func TestAPIPullUpdate(t *testing.T) {
 func TestAPIPullUpdateByRebase(t *testing.T) {
 	onGiteaRun(t, func(t *testing.T, giteaURL *url.URL) {
 		//Create PR to test
-		user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-		org26 := models.AssertExistsAndLoadBean(t, &models.User{ID: 26}).(*models.User)
+		user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+		org26 := db.AssertExistsAndLoadBean(t, &models.User{ID: 26}).(*models.User)
 		pr := createOutdatedPR(t, user, org26)
 
 		//Test GetDiverging
@@ -162,7 +163,7 @@ func createOutdatedPR(t *testing.T, actor, forkOrg *models.User) *models.PullReq
 	err = pull_service.NewPullRequest(baseRepo, pullIssue, nil, nil, pullRequest, nil)
 	assert.NoError(t, err)
 
-	issue := models.AssertExistsAndLoadBean(t, &models.Issue{Title: "Test Pull -to-update-"}).(*models.Issue)
+	issue := db.AssertExistsAndLoadBean(t, &models.Issue{Title: "Test Pull -to-update-"}).(*models.Issue)
 	pr, err := models.GetPullRequestByIssueID(issue.ID)
 	assert.NoError(t, err)
 
diff --git a/integrations/release_test.go b/integrations/release_test.go
index 4458387ef..2e9de3169 100644
--- a/integrations/release_test.go
+++ b/integrations/release_test.go
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/test"
 
@@ -133,7 +134,7 @@ func TestCreateReleasePaging(t *testing.T) {
 func TestViewReleaseListNoLogin(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 
 	link := repo.Link() + "/releases"
 
@@ -159,7 +160,7 @@ func TestViewReleaseListNoLogin(t *testing.T) {
 func TestViewReleaseListLogin(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 
 	link := repo.Link() + "/releases"
 
@@ -190,7 +191,7 @@ func TestViewReleaseListLogin(t *testing.T) {
 func TestViewTagsList(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 
 	link := repo.Link() + "/tags"
 
diff --git a/integrations/repo_fork_test.go b/integrations/repo_fork_test.go
index d0542c1a7..f9a994fd8 100644
--- a/integrations/repo_fork_test.go
+++ b/integrations/repo_fork_test.go
@@ -11,12 +11,13 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func testRepoFork(t *testing.T, session *TestSession, ownerName, repoName, forkOwnerName, forkRepoName string) *httptest.ResponseRecorder {
-	forkOwner := models.AssertExistsAndLoadBean(t, &models.User{Name: forkOwnerName}).(*models.User)
+	forkOwner := db.AssertExistsAndLoadBean(t, &models.User{Name: forkOwnerName}).(*models.User)
 
 	// Step0: check the existence of the to-fork repo
 	req := NewRequestf(t, "GET", "/%s/%s", forkOwnerName, forkRepoName)
diff --git a/integrations/repo_generate_test.go b/integrations/repo_generate_test.go
index 1aa91236e..7afce7474 100644
--- a/integrations/repo_generate_test.go
+++ b/integrations/repo_generate_test.go
@@ -11,12 +11,13 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func testRepoGenerate(t *testing.T, session *TestSession, templateOwnerName, templateRepoName, generateOwnerName, generateRepoName string) *httptest.ResponseRecorder {
-	generateOwner := models.AssertExistsAndLoadBean(t, &models.User{Name: generateOwnerName}).(*models.User)
+	generateOwner := db.AssertExistsAndLoadBean(t, &models.User{Name: generateOwnerName}).(*models.User)
 
 	// Step0: check the existence of the generated repo
 	req := NewRequestf(t, "GET", "/%s/%s", generateOwnerName, generateRepoName)
diff --git a/integrations/repo_tag_test.go b/integrations/repo_tag_test.go
index eb3f2b47f..05505a644 100644
--- a/integrations/repo_tag_test.go
+++ b/integrations/repo_tag_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/services/release"
@@ -20,8 +21,8 @@ import (
 func TestCreateNewTagProtected(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	t.Run("API", func(t *testing.T) {
 		defer PrintCurrentTest(t)()
diff --git a/integrations/repo_watch_test.go b/integrations/repo_watch_test.go
index d96b014a7..7ae9f1fe7 100644
--- a/integrations/repo_watch_test.go
+++ b/integrations/repo_watch_test.go
@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 )
 
@@ -17,8 +18,8 @@ func TestRepoWatch(t *testing.T) {
 		// Test round-trip auto-watch
 		setting.Service.AutoWatchOnChanges = true
 		session := loginUser(t, "user2")
-		models.AssertNotExistsBean(t, &models.Watch{UserID: 2, RepoID: 3})
+		db.AssertNotExistsBean(t, &models.Watch{UserID: 2, RepoID: 3})
 		testEditFile(t, session, "user3", "repo3", "master", "README.md", "Hello, World (Edited for watch)\n")
-		models.AssertExistsAndLoadBean(t, &models.Watch{UserID: 2, RepoID: 3, Mode: models.RepoWatchModeAuto})
+		db.AssertExistsAndLoadBean(t, &models.Watch{UserID: 2, RepoID: 3, Mode: models.RepoWatchModeAuto})
 	})
 }
diff --git a/integrations/repofiles_delete_test.go b/integrations/repofiles_delete_test.go
index 1fa316c41..22fef4b03 100644
--- a/integrations/repofiles_delete_test.go
+++ b/integrations/repofiles_delete_test.go
@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/repofiles"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/test"
@@ -66,7 +67,7 @@ func TestDeleteRepoFile(t *testing.T) {
 
 func testDeleteRepoFile(t *testing.T, u *url.URL) {
 	// setup
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1")
 	ctx.SetParams(":id", "1")
 	test.LoadRepo(t, ctx, 1)
@@ -105,7 +106,7 @@ func TestDeleteRepoFileWithoutBranchNames(t *testing.T) {
 
 func testDeleteRepoFileWithoutBranchNames(t *testing.T, u *url.URL) {
 	// setup
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1")
 	ctx.SetParams(":id", "1")
 	test.LoadRepo(t, ctx, 1)
@@ -135,7 +136,7 @@ func testDeleteRepoFileWithoutBranchNames(t *testing.T, u *url.URL) {
 
 func TestDeleteRepoFileErrors(t *testing.T) {
 	// setup
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1")
 	ctx.SetParams(":id", "1")
 	test.LoadRepo(t, ctx, 1)
diff --git a/integrations/signin_test.go b/integrations/signin_test.go
index 390bf6408..081f87f0b 100644
--- a/integrations/signin_test.go
+++ b/integrations/signin_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/unknwon/i18n"
@@ -33,13 +34,13 @@ func testLoginFailed(t *testing.T, username, password, message string) {
 func TestSignin(t *testing.T) {
 	defer prepareTestEnv(t)()
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 
 	// add new user with user2's email
 	user.Name = "testuser"
 	user.LowerName = strings.ToLower(user.Name)
 	user.ID = 0
-	models.AssertSuccessfulInsert(t, user)
+	db.AssertSuccessfulInsert(t, user)
 
 	samples := []struct {
 		username string
diff --git a/integrations/signup_test.go b/integrations/signup_test.go
index 66ff8ac2d..dccb1f676 100644
--- a/integrations/signup_test.go
+++ b/integrations/signup_test.go
@@ -11,6 +11,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	"github.com/stretchr/testify/assert"
 	"github.com/unknwon/i18n"
@@ -52,7 +53,7 @@ func TestSignupAsRestricted(t *testing.T) {
 	req = NewRequest(t, "GET", "/restrictedUser")
 	MakeRequest(t, req, http.StatusOK)
 
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{Name: "restrictedUser"}).(*models.User)
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{Name: "restrictedUser"}).(*models.User)
 	assert.True(t, user2.IsRestricted)
 }
 
diff --git a/integrations/user_avatar_test.go b/integrations/user_avatar_test.go
index 1a3a85128..c909fd685 100644
--- a/integrations/user_avatar_test.go
+++ b/integrations/user_avatar_test.go
@@ -15,13 +15,14 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/avatar"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestUserAvatar(t *testing.T) {
 	onGiteaRun(t, func(t *testing.T, u *url.URL) {
-		user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User) // owner of the repo3, is an org
+		user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User) // owner of the repo3, is an org
 
 		seed := user2.Email
 		if len(seed) == 0 {
@@ -71,7 +72,7 @@ func TestUserAvatar(t *testing.T) {
 
 		session.MakeRequest(t, req, http.StatusFound)
 
-		user2 = models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User) // owner of the repo3, is an org
+		user2 = db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User) // owner of the repo3, is an org
 
 		req = NewRequest(t, "GET", user2.AvatarLink())
 		resp := session.MakeRequest(t, req, http.StatusFound)
diff --git a/integrations/user_test.go b/integrations/user_test.go
index 199d5e242..f9e507afb 100644
--- a/integrations/user_test.go
+++ b/integrations/user_test.go
@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/test"
 
 	"github.com/stretchr/testify/assert"
@@ -34,8 +35,8 @@ func TestRenameUsername(t *testing.T) {
 	})
 	session.MakeRequest(t, req, http.StatusFound)
 
-	models.AssertExistsAndLoadBean(t, &models.User{Name: "newUsername"})
-	models.AssertNotExistsBean(t, &models.User{Name: "user2"})
+	db.AssertExistsAndLoadBean(t, &models.User{Name: "newUsername"})
+	db.AssertNotExistsBean(t, &models.User{Name: "user2"})
 }
 
 func TestRenameInvalidUsername(t *testing.T) {
@@ -66,7 +67,7 @@ func TestRenameInvalidUsername(t *testing.T) {
 			i18n.Tr("en", "form.alpha_dash_dot_error"),
 		)
 
-		models.AssertNotExistsBean(t, &models.User{Name: invalidUsername})
+		db.AssertNotExistsBean(t, &models.User{Name: invalidUsername})
 	}
 }
 
@@ -112,7 +113,7 @@ func TestRenameReservedUsername(t *testing.T) {
 			i18n.Tr("en", "user.form.name_reserved", reservedUsername),
 		)
 
-		models.AssertNotExistsBean(t, &models.User{Name: reservedUsername})
+		db.AssertNotExistsBean(t, &models.User{Name: reservedUsername})
 	}
 }
 
diff --git a/integrations/xss_test.go b/integrations/xss_test.go
index 2d83e1e10..427c97de2 100644
--- a/integrations/xss_test.go
+++ b/integrations/xss_test.go
@@ -9,13 +9,14 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestXSSUserFullName(t *testing.T) {
 	defer prepareTestEnv(t)()
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	const fullName = `name & <script class="evil">alert('Oh no!');</script>`
 
 	session := loginUser(t, user.Name)
diff --git a/models/access.go b/models/access.go
index 5d0b0b06c..e23062904 100644
--- a/models/access.go
+++ b/models/access.go
@@ -8,6 +8,7 @@ package models
 import (
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 )
 
@@ -71,7 +72,11 @@ type Access struct {
 	Mode   AccessMode
 }
 
-func accessLevel(e Engine, user *User, repo *Repository) (AccessMode, error) {
+func init() {
+	db.RegisterModel(new(Access))
+}
+
+func accessLevel(e db.Engine, user *User, repo *Repository) (AccessMode, error) {
 	mode := AccessModeNone
 	var userID int64
 	restricted := false
@@ -111,7 +116,7 @@ func (repoAccess) TableName() string {
 
 // GetRepositoryAccesses finds all repositories with their access mode where a user has access but does not own.
 func (user *User) GetRepositoryAccesses() (map[*Repository]AccessMode, error) {
-	rows, err := x.
+	rows, err := db.DefaultContext().Engine().
 		Join("INNER", "repository", "repository.id = access.repo_id").
 		Where("access.user_id = ?", user.ID).
 		And("repository.owner_id <> ?", user.ID).
@@ -146,7 +151,7 @@ func (user *User) GetRepositoryAccesses() (map[*Repository]AccessMode, error) {
 // GetAccessibleRepositories finds repositories which the user has access but does not own.
 // If limit is smaller than 1 means returns all found results.
 func (user *User) GetAccessibleRepositories(limit int) (repos []*Repository, _ error) {
-	sess := x.
+	sess := db.DefaultContext().Engine().
 		Where("owner_id !=? ", user.ID).
 		Desc("updated_unix")
 	if limit > 0 {
@@ -185,7 +190,7 @@ func updateUserAccess(accessMap map[int64]*userAccess, user *User, mode AccessMo
 }
 
 // FIXME: do cross-comparison so reduce deletions and additions to the minimum?
-func (repo *Repository) refreshAccesses(e Engine, accessMap map[int64]*userAccess) (err error) {
+func (repo *Repository) refreshAccesses(e db.Engine, accessMap map[int64]*userAccess) (err error) {
 	minMode := AccessModeRead
 	if !repo.IsPrivate {
 		minMode = AccessModeWrite
@@ -219,7 +224,7 @@ func (repo *Repository) refreshAccesses(e Engine, accessMap map[int64]*userAcces
 }
 
 // refreshCollaboratorAccesses retrieves repository collaborations with their access modes.
-func (repo *Repository) refreshCollaboratorAccesses(e Engine, accessMap map[int64]*userAccess) error {
+func (repo *Repository) refreshCollaboratorAccesses(e db.Engine, accessMap map[int64]*userAccess) error {
 	collaborators, err := repo.getCollaborators(e, ListOptions{})
 	if err != nil {
 		return fmt.Errorf("getCollaborations: %v", err)
@@ -233,7 +238,7 @@ func (repo *Repository) refreshCollaboratorAccesses(e Engine, accessMap map[int6
 // recalculateTeamAccesses recalculates new accesses for teams of an organization
 // except the team whose ID is given. It is used to assign a team ID when
 // remove repository from that team.
-func (repo *Repository) recalculateTeamAccesses(e Engine, ignTeamID int64) (err error) {
+func (repo *Repository) recalculateTeamAccesses(e db.Engine, ignTeamID int64) (err error) {
 	accessMap := make(map[int64]*userAccess, 20)
 
 	if err = repo.getOwner(e); err != nil {
@@ -276,7 +281,7 @@ func (repo *Repository) recalculateTeamAccesses(e Engine, ignTeamID int64) (err
 
 // recalculateUserAccess recalculates new access for a single user
 // Usable if we know access only affected one user
-func (repo *Repository) recalculateUserAccess(e Engine, uid int64) (err error) {
+func (repo *Repository) recalculateUserAccess(e db.Engine, uid int64) (err error) {
 	minMode := AccessModeRead
 	if !repo.IsPrivate {
 		minMode = AccessModeWrite
@@ -323,7 +328,7 @@ func (repo *Repository) recalculateUserAccess(e Engine, uid int64) (err error) {
 	return nil
 }
 
-func (repo *Repository) recalculateAccesses(e Engine) error {
+func (repo *Repository) recalculateAccesses(e db.Engine) error {
 	if repo.Owner.IsOrganization() {
 		return repo.recalculateTeamAccesses(e, 0)
 	}
@@ -337,5 +342,5 @@ func (repo *Repository) recalculateAccesses(e Engine) error {
 
 // RecalculateAccesses recalculates all accesses for repository.
 func (repo *Repository) RecalculateAccesses() error {
-	return repo.recalculateAccesses(x)
+	return repo.recalculateAccesses(db.DefaultContext().Engine())
 }
diff --git a/models/access_test.go b/models/access_test.go
index c134ab98d..875b2a0c1 100644
--- a/models/access_test.go
+++ b/models/access_test.go
@@ -7,27 +7,28 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestAccessLevel(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user2 := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
-	user5 := AssertExistsAndLoadBean(t, &User{ID: 5}).(*User)
-	user29 := AssertExistsAndLoadBean(t, &User{ID: 29}).(*User)
+	user2 := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user5 := db.AssertExistsAndLoadBean(t, &User{ID: 5}).(*User)
+	user29 := db.AssertExistsAndLoadBean(t, &User{ID: 29}).(*User)
 	// A public repository owned by User 2
-	repo1 := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	repo1 := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
 	assert.False(t, repo1.IsPrivate)
 	// A private repository owned by Org 3
-	repo3 := AssertExistsAndLoadBean(t, &Repository{ID: 3}).(*Repository)
+	repo3 := db.AssertExistsAndLoadBean(t, &Repository{ID: 3}).(*Repository)
 	assert.True(t, repo3.IsPrivate)
 
 	// Another public repository
-	repo4 := AssertExistsAndLoadBean(t, &Repository{ID: 4}).(*Repository)
+	repo4 := db.AssertExistsAndLoadBean(t, &Repository{ID: 4}).(*Repository)
 	assert.False(t, repo4.IsPrivate)
 	// org. owned private repo
-	repo24 := AssertExistsAndLoadBean(t, &Repository{ID: 24}).(*Repository)
+	repo24 := db.AssertExistsAndLoadBean(t, &Repository{ID: 24}).(*Repository)
 
 	level, err := AccessLevel(user2, repo1)
 	assert.NoError(t, err)
@@ -62,15 +63,15 @@ func TestAccessLevel(t *testing.T) {
 }
 
 func TestHasAccess(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user1 := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
-	user2 := AssertExistsAndLoadBean(t, &User{ID: 5}).(*User)
+	user1 := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user2 := db.AssertExistsAndLoadBean(t, &User{ID: 5}).(*User)
 	// A public repository owned by User 2
-	repo1 := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	repo1 := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
 	assert.False(t, repo1.IsPrivate)
 	// A private repository owned by Org 3
-	repo2 := AssertExistsAndLoadBean(t, &Repository{ID: 3}).(*Repository)
+	repo2 := db.AssertExistsAndLoadBean(t, &Repository{ID: 3}).(*Repository)
 	assert.True(t, repo2.IsPrivate)
 
 	has, err := HasAccess(user1.ID, repo1)
@@ -88,33 +89,33 @@ func TestHasAccess(t *testing.T) {
 }
 
 func TestUser_GetRepositoryAccesses(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user1 := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	user1 := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 	accesses, err := user1.GetRepositoryAccesses()
 	assert.NoError(t, err)
 	assert.Len(t, accesses, 0)
 
-	user29 := AssertExistsAndLoadBean(t, &User{ID: 29}).(*User)
+	user29 := db.AssertExistsAndLoadBean(t, &User{ID: 29}).(*User)
 	accesses, err = user29.GetRepositoryAccesses()
 	assert.NoError(t, err)
 	assert.Len(t, accesses, 2)
 }
 
 func TestUser_GetAccessibleRepositories(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user1 := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	user1 := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 	repos, err := user1.GetAccessibleRepositories(0)
 	assert.NoError(t, err)
 	assert.Len(t, repos, 0)
 
-	user2 := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user2 := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	repos, err = user2.GetAccessibleRepositories(0)
 	assert.NoError(t, err)
 	assert.Len(t, repos, 4)
 
-	user29 := AssertExistsAndLoadBean(t, &User{ID: 29}).(*User)
+	user29 := db.AssertExistsAndLoadBean(t, &User{ID: 29}).(*User)
 	repos, err = user29.GetAccessibleRepositories(0)
 	assert.NoError(t, err)
 	assert.Len(t, repos, 2)
@@ -122,16 +123,16 @@ func TestUser_GetAccessibleRepositories(t *testing.T) {
 
 func TestRepository_RecalculateAccesses(t *testing.T) {
 	// test with organization repo
-	assert.NoError(t, PrepareTestDatabase())
-	repo1 := AssertExistsAndLoadBean(t, &Repository{ID: 3}).(*Repository)
+	assert.NoError(t, db.PrepareTestDatabase())
+	repo1 := db.AssertExistsAndLoadBean(t, &Repository{ID: 3}).(*Repository)
 	assert.NoError(t, repo1.GetOwner())
 
-	_, err := x.Delete(&Collaboration{UserID: 2, RepoID: 3})
+	_, err := db.DefaultContext().Engine().Delete(&Collaboration{UserID: 2, RepoID: 3})
 	assert.NoError(t, err)
 	assert.NoError(t, repo1.RecalculateAccesses())
 
 	access := &Access{UserID: 2, RepoID: 3}
-	has, err := x.Get(access)
+	has, err := db.DefaultContext().Engine().Get(access)
 	assert.NoError(t, err)
 	assert.True(t, has)
 	assert.Equal(t, AccessModeOwner, access.Mode)
@@ -139,25 +140,25 @@ func TestRepository_RecalculateAccesses(t *testing.T) {
 
 func TestRepository_RecalculateAccesses2(t *testing.T) {
 	// test with non-organization repo
-	assert.NoError(t, PrepareTestDatabase())
-	repo1 := AssertExistsAndLoadBean(t, &Repository{ID: 4}).(*Repository)
+	assert.NoError(t, db.PrepareTestDatabase())
+	repo1 := db.AssertExistsAndLoadBean(t, &Repository{ID: 4}).(*Repository)
 	assert.NoError(t, repo1.GetOwner())
 
-	_, err := x.Delete(&Collaboration{UserID: 4, RepoID: 4})
+	_, err := db.DefaultContext().Engine().Delete(&Collaboration{UserID: 4, RepoID: 4})
 	assert.NoError(t, err)
 	assert.NoError(t, repo1.RecalculateAccesses())
 
-	has, err := x.Get(&Access{UserID: 4, RepoID: 4})
+	has, err := db.DefaultContext().Engine().Get(&Access{UserID: 4, RepoID: 4})
 	assert.NoError(t, err)
 	assert.False(t, has)
 }
 
 func TestRepository_RecalculateAccesses3(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	team5 := AssertExistsAndLoadBean(t, &Team{ID: 5}).(*Team)
-	user29 := AssertExistsAndLoadBean(t, &User{ID: 29}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	team5 := db.AssertExistsAndLoadBean(t, &Team{ID: 5}).(*Team)
+	user29 := db.AssertExistsAndLoadBean(t, &User{ID: 29}).(*User)
 
-	has, err := x.Get(&Access{UserID: 29, RepoID: 23})
+	has, err := db.DefaultContext().Engine().Get(&Access{UserID: 29, RepoID: 23})
 	assert.NoError(t, err)
 	assert.False(t, has)
 
@@ -165,7 +166,7 @@ func TestRepository_RecalculateAccesses3(t *testing.T) {
 	// even though repo 23 is public
 	assert.NoError(t, AddTeamMember(team5, user29.ID))
 
-	has, err = x.Get(&Access{UserID: 29, RepoID: 23})
+	has, err = db.DefaultContext().Engine().Get(&Access{UserID: 29, RepoID: 23})
 	assert.NoError(t, err)
 	assert.True(t, has)
 }
diff --git a/models/action.go b/models/action.go
index 3462a5e3f..f957e2b0c 100644
--- a/models/action.go
+++ b/models/action.go
@@ -12,6 +12,7 @@ import (
 	"strings"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
@@ -74,6 +75,10 @@ type Action struct {
 	CreatedUnix timeutil.TimeStamp `xorm:"INDEX created"`
 }
 
+func init() {
+	db.RegisterModel(new(Action))
+}
+
 // GetOpType gets the ActionType of this action.
 func (a *Action) GetOpType() ActionType {
 	return a.OpType
@@ -203,10 +208,10 @@ func GetRepositoryFromMatch(ownerName, repoName string) (*Repository, error) {
 
 // GetCommentLink returns link to action comment.
 func (a *Action) GetCommentLink() string {
-	return a.getCommentLink(x)
+	return a.getCommentLink(db.DefaultContext().Engine())
 }
 
-func (a *Action) getCommentLink(e Engine) string {
+func (a *Action) getCommentLink(e db.Engine) string {
 	if a == nil {
 		return "#"
 	}
@@ -312,7 +317,7 @@ func GetFeeds(opts GetFeedsOptions) ([]*Action, error) {
 
 	actions := make([]*Action, 0, setting.UI.FeedPagingNum)
 
-	if err := x.Limit(setting.UI.FeedPagingNum).Desc("id").Where(cond).Find(&actions); err != nil {
+	if err := db.DefaultContext().Engine().Limit(setting.UI.FeedPagingNum).Desc("id").Where(cond).Find(&actions); err != nil {
 		return nil, fmt.Errorf("Find: %v", err)
 	}
 
@@ -403,6 +408,6 @@ func DeleteOldActions(olderThan time.Duration) (err error) {
 		return nil
 	}
 
-	_, err = x.Where("created_unix < ?", time.Now().Add(-olderThan).Unix()).Delete(&Action{})
+	_, err = db.DefaultContext().Engine().Where("created_unix < ?", time.Now().Add(-olderThan).Unix()).Delete(&Action{})
 	return
 }
diff --git a/models/action_list.go b/models/action_list.go
index 6f726f4b3..a0ceef6be 100644
--- a/models/action_list.go
+++ b/models/action_list.go
@@ -4,7 +4,11 @@
 
 package models
 
-import "fmt"
+import (
+	"fmt"
+
+	"code.gitea.io/gitea/models/db"
+)
 
 // ActionList defines a list of actions
 type ActionList []*Action
@@ -19,7 +23,7 @@ func (actions ActionList) getUserIDs() []int64 {
 	return keysInt64(userIDs)
 }
 
-func (actions ActionList) loadUsers(e Engine) ([]*User, error) {
+func (actions ActionList) loadUsers(e db.Engine) ([]*User, error) {
 	if len(actions) == 0 {
 		return nil, nil
 	}
@@ -41,7 +45,7 @@ func (actions ActionList) loadUsers(e Engine) ([]*User, error) {
 
 // LoadUsers loads actions' all users
 func (actions ActionList) LoadUsers() ([]*User, error) {
-	return actions.loadUsers(x)
+	return actions.loadUsers(db.DefaultContext().Engine())
 }
 
 func (actions ActionList) getRepoIDs() []int64 {
@@ -54,7 +58,7 @@ func (actions ActionList) getRepoIDs() []int64 {
 	return keysInt64(repoIDs)
 }
 
-func (actions ActionList) loadRepositories(e Engine) ([]*Repository, error) {
+func (actions ActionList) loadRepositories(e db.Engine) ([]*Repository, error) {
 	if len(actions) == 0 {
 		return nil, nil
 	}
@@ -76,11 +80,11 @@ func (actions ActionList) loadRepositories(e Engine) ([]*Repository, error) {
 
 // LoadRepositories loads actions' all repositories
 func (actions ActionList) LoadRepositories() ([]*Repository, error) {
-	return actions.loadRepositories(x)
+	return actions.loadRepositories(db.DefaultContext().Engine())
 }
 
 // loadAttributes loads all attributes
-func (actions ActionList) loadAttributes(e Engine) (err error) {
+func (actions ActionList) loadAttributes(e db.Engine) (err error) {
 	if _, err = actions.loadUsers(e); err != nil {
 		return
 	}
@@ -94,5 +98,5 @@ func (actions ActionList) loadAttributes(e Engine) (err error) {
 
 // LoadAttributes loads attributes of the actions
 func (actions ActionList) LoadAttributes() error {
-	return actions.loadAttributes(x)
+	return actions.loadAttributes(db.DefaultContext().Engine())
 }
diff --git a/models/action_test.go b/models/action_test.go
index 6dab676a7..78090e3aa 100644
--- a/models/action_test.go
+++ b/models/action_test.go
@@ -8,23 +8,24 @@ import (
 	"path"
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestAction_GetRepoPath(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	repo := AssertExistsAndLoadBean(t, &Repository{}).(*Repository)
-	owner := AssertExistsAndLoadBean(t, &User{ID: repo.OwnerID}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	repo := db.AssertExistsAndLoadBean(t, &Repository{}).(*Repository)
+	owner := db.AssertExistsAndLoadBean(t, &User{ID: repo.OwnerID}).(*User)
 	action := &Action{RepoID: repo.ID}
 	assert.Equal(t, path.Join(owner.Name, repo.Name), action.GetRepoPath())
 }
 
 func TestAction_GetRepoLink(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	repo := AssertExistsAndLoadBean(t, &Repository{}).(*Repository)
-	owner := AssertExistsAndLoadBean(t, &User{ID: repo.OwnerID}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	repo := db.AssertExistsAndLoadBean(t, &Repository{}).(*Repository)
+	owner := db.AssertExistsAndLoadBean(t, &User{ID: repo.OwnerID}).(*User)
 	action := &Action{RepoID: repo.ID}
 	setting.AppSubURL = "/suburl"
 	expected := path.Join(setting.AppSubURL, owner.Name, repo.Name)
@@ -33,8 +34,8 @@ func TestAction_GetRepoLink(t *testing.T) {
 
 func TestGetFeeds(t *testing.T) {
 	// test with an individual user
-	assert.NoError(t, PrepareTestDatabase())
-	user := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 
 	actions, err := GetFeeds(GetFeedsOptions{
 		RequestedUser:   user,
@@ -61,9 +62,9 @@ func TestGetFeeds(t *testing.T) {
 
 func TestGetFeeds2(t *testing.T) {
 	// test with an organization user
-	assert.NoError(t, PrepareTestDatabase())
-	org := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
-	user := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	org := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 
 	actions, err := GetFeeds(GetFeedsOptions{
 		RequestedUser:   org,
diff --git a/models/admin.go b/models/admin.go
index 3a784d669..084942ff5 100644
--- a/models/admin.go
+++ b/models/admin.go
@@ -8,6 +8,7 @@ package models
 import (
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/storage"
 	"code.gitea.io/gitea/modules/timeutil"
@@ -32,6 +33,10 @@ type Notice struct {
 	CreatedUnix timeutil.TimeStamp `xorm:"INDEX created"`
 }
 
+func init() {
+	db.RegisterModel(new(Notice))
+}
+
 // TrStr returns a translation format string.
 func (n *Notice) TrStr() string {
 	return fmt.Sprintf("admin.notices.type_%d", n.Type)
@@ -39,10 +44,10 @@ func (n *Notice) TrStr() string {
 
 // CreateNotice creates new system notice.
 func CreateNotice(tp NoticeType, desc string, args ...interface{}) error {
-	return createNotice(x, tp, desc, args...)
+	return createNotice(db.DefaultContext().Engine(), tp, desc, args...)
 }
 
-func createNotice(e Engine, tp NoticeType, desc string, args ...interface{}) error {
+func createNotice(e db.Engine, tp NoticeType, desc string, args ...interface{}) error {
 	if len(args) > 0 {
 		desc = fmt.Sprintf(desc, args...)
 	}
@@ -56,22 +61,22 @@ func createNotice(e Engine, tp NoticeType, desc string, args ...interface{}) err
 
 // CreateRepositoryNotice creates new system notice with type NoticeRepository.
 func CreateRepositoryNotice(desc string, args ...interface{}) error {
-	return createNotice(x, NoticeRepository, desc, args...)
+	return createNotice(db.DefaultContext().Engine(), NoticeRepository, desc, args...)
 }
 
 // RemoveAllWithNotice removes all directories in given path and
 // creates a system notice when error occurs.
 func RemoveAllWithNotice(title, path string) {
-	removeAllWithNotice(x, title, path)
+	removeAllWithNotice(db.DefaultContext().Engine(), title, path)
 }
 
 // RemoveStorageWithNotice removes a file from the storage and
 // creates a system notice when error occurs.
 func RemoveStorageWithNotice(bucket storage.ObjectStorage, title, path string) {
-	removeStorageWithNotice(x, bucket, title, path)
+	removeStorageWithNotice(db.DefaultContext().Engine(), bucket, title, path)
 }
 
-func removeStorageWithNotice(e Engine, bucket storage.ObjectStorage, title, path string) {
+func removeStorageWithNotice(e db.Engine, bucket storage.ObjectStorage, title, path string) {
 	if err := bucket.Delete(path); err != nil {
 		desc := fmt.Sprintf("%s [%s]: %v", title, path, err)
 		log.Warn(title+" [%s]: %v", path, err)
@@ -81,7 +86,7 @@ func removeStorageWithNotice(e Engine, bucket storage.ObjectStorage, title, path
 	}
 }
 
-func removeAllWithNotice(e Engine, title, path string) {
+func removeAllWithNotice(e db.Engine, title, path string) {
 	if err := util.RemoveAll(path); err != nil {
 		desc := fmt.Sprintf("%s [%s]: %v", title, path, err)
 		log.Warn(title+" [%s]: %v", path, err)
@@ -93,14 +98,14 @@ func removeAllWithNotice(e Engine, title, path string) {
 
 // CountNotices returns number of notices.
 func CountNotices() int64 {
-	count, _ := x.Count(new(Notice))
+	count, _ := db.DefaultContext().Engine().Count(new(Notice))
 	return count
 }
 
 // Notices returns notices in given page.
 func Notices(page, pageSize int) ([]*Notice, error) {
 	notices := make([]*Notice, 0, pageSize)
-	return notices, x.
+	return notices, db.DefaultContext().Engine().
 		Limit(pageSize, (page-1)*pageSize).
 		Desc("id").
 		Find(&notices)
@@ -108,18 +113,18 @@ func Notices(page, pageSize int) ([]*Notice, error) {
 
 // DeleteNotice deletes a system notice by given ID.
 func DeleteNotice(id int64) error {
-	_, err := x.ID(id).Delete(new(Notice))
+	_, err := db.DefaultContext().Engine().ID(id).Delete(new(Notice))
 	return err
 }
 
 // DeleteNotices deletes all notices with ID from start to end (inclusive).
 func DeleteNotices(start, end int64) error {
 	if start == 0 && end == 0 {
-		_, err := x.Exec("DELETE FROM notice")
+		_, err := db.DefaultContext().Engine().Exec("DELETE FROM notice")
 		return err
 	}
 
-	sess := x.Where("id >= ?", start)
+	sess := db.DefaultContext().Engine().Where("id >= ?", start)
 	if end > 0 {
 		sess.And("id <= ?", end)
 	}
@@ -132,7 +137,7 @@ func DeleteNoticesByIDs(ids []int64) error {
 	if len(ids) == 0 {
 		return nil
 	}
-	_, err := x.
+	_, err := db.DefaultContext().Engine().
 		In("id", ids).
 		Delete(new(Notice))
 	return err
@@ -141,7 +146,7 @@ func DeleteNoticesByIDs(ids []int64) error {
 // GetAdminUser returns the first administrator
 func GetAdminUser() (*User, error) {
 	var admin User
-	has, err := x.Where("is_admin=?", true).Get(&admin)
+	has, err := db.DefaultContext().Engine().Where("is_admin=?", true).Get(&admin)
 	if err != nil {
 		return nil, err
 	} else if !has {
diff --git a/models/admin_test.go b/models/admin_test.go
index b4383cb2d..316ed5cb6 100644
--- a/models/admin_test.go
+++ b/models/admin_test.go
@@ -7,6 +7,7 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -19,38 +20,38 @@ func TestNotice_TrStr(t *testing.T) {
 }
 
 func TestCreateNotice(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	noticeBean := &Notice{
 		Type:        NoticeRepository,
 		Description: "test description",
 	}
-	AssertNotExistsBean(t, noticeBean)
+	db.AssertNotExistsBean(t, noticeBean)
 	assert.NoError(t, CreateNotice(noticeBean.Type, noticeBean.Description))
-	AssertExistsAndLoadBean(t, noticeBean)
+	db.AssertExistsAndLoadBean(t, noticeBean)
 }
 
 func TestCreateRepositoryNotice(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	noticeBean := &Notice{
 		Type:        NoticeRepository,
 		Description: "test description",
 	}
-	AssertNotExistsBean(t, noticeBean)
+	db.AssertNotExistsBean(t, noticeBean)
 	assert.NoError(t, CreateRepositoryNotice(noticeBean.Description))
-	AssertExistsAndLoadBean(t, noticeBean)
+	db.AssertExistsAndLoadBean(t, noticeBean)
 }
 
 // TODO TestRemoveAllWithNotice
 
 func TestCountNotices(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	assert.Equal(t, int64(3), CountNotices())
 }
 
 func TestNotices(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	notices, err := Notices(1, 2)
 	assert.NoError(t, err)
@@ -67,47 +68,47 @@ func TestNotices(t *testing.T) {
 }
 
 func TestDeleteNotice(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	AssertExistsAndLoadBean(t, &Notice{ID: 3})
+	db.AssertExistsAndLoadBean(t, &Notice{ID: 3})
 	assert.NoError(t, DeleteNotice(3))
-	AssertNotExistsBean(t, &Notice{ID: 3})
+	db.AssertNotExistsBean(t, &Notice{ID: 3})
 }
 
 func TestDeleteNotices(t *testing.T) {
 	// delete a non-empty range
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	AssertExistsAndLoadBean(t, &Notice{ID: 1})
-	AssertExistsAndLoadBean(t, &Notice{ID: 2})
-	AssertExistsAndLoadBean(t, &Notice{ID: 3})
+	db.AssertExistsAndLoadBean(t, &Notice{ID: 1})
+	db.AssertExistsAndLoadBean(t, &Notice{ID: 2})
+	db.AssertExistsAndLoadBean(t, &Notice{ID: 3})
 	assert.NoError(t, DeleteNotices(1, 2))
-	AssertNotExistsBean(t, &Notice{ID: 1})
-	AssertNotExistsBean(t, &Notice{ID: 2})
-	AssertExistsAndLoadBean(t, &Notice{ID: 3})
+	db.AssertNotExistsBean(t, &Notice{ID: 1})
+	db.AssertNotExistsBean(t, &Notice{ID: 2})
+	db.AssertExistsAndLoadBean(t, &Notice{ID: 3})
 }
 
 func TestDeleteNotices2(t *testing.T) {
 	// delete an empty range
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	AssertExistsAndLoadBean(t, &Notice{ID: 1})
-	AssertExistsAndLoadBean(t, &Notice{ID: 2})
-	AssertExistsAndLoadBean(t, &Notice{ID: 3})
+	db.AssertExistsAndLoadBean(t, &Notice{ID: 1})
+	db.AssertExistsAndLoadBean(t, &Notice{ID: 2})
+	db.AssertExistsAndLoadBean(t, &Notice{ID: 3})
 	assert.NoError(t, DeleteNotices(3, 2))
-	AssertExistsAndLoadBean(t, &Notice{ID: 1})
-	AssertExistsAndLoadBean(t, &Notice{ID: 2})
-	AssertExistsAndLoadBean(t, &Notice{ID: 3})
+	db.AssertExistsAndLoadBean(t, &Notice{ID: 1})
+	db.AssertExistsAndLoadBean(t, &Notice{ID: 2})
+	db.AssertExistsAndLoadBean(t, &Notice{ID: 3})
 }
 
 func TestDeleteNoticesByIDs(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	AssertExistsAndLoadBean(t, &Notice{ID: 1})
-	AssertExistsAndLoadBean(t, &Notice{ID: 2})
-	AssertExistsAndLoadBean(t, &Notice{ID: 3})
+	db.AssertExistsAndLoadBean(t, &Notice{ID: 1})
+	db.AssertExistsAndLoadBean(t, &Notice{ID: 2})
+	db.AssertExistsAndLoadBean(t, &Notice{ID: 3})
 	assert.NoError(t, DeleteNoticesByIDs([]int64{1, 3}))
-	AssertNotExistsBean(t, &Notice{ID: 1})
-	AssertExistsAndLoadBean(t, &Notice{ID: 2})
-	AssertNotExistsBean(t, &Notice{ID: 3})
+	db.AssertNotExistsBean(t, &Notice{ID: 1})
+	db.AssertExistsAndLoadBean(t, &Notice{ID: 2})
+	db.AssertNotExistsBean(t, &Notice{ID: 3})
 }
diff --git a/models/attachment.go b/models/attachment.go
index 96048db00..36f318db6 100644
--- a/models/attachment.go
+++ b/models/attachment.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"path"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/storage"
 	"code.gitea.io/gitea/modules/timeutil"
@@ -30,10 +31,14 @@ type Attachment struct {
 	CreatedUnix   timeutil.TimeStamp `xorm:"created"`
 }
 
+func init() {
+	db.RegisterModel(new(Attachment))
+}
+
 // IncreaseDownloadCount is update download count + 1
 func (a *Attachment) IncreaseDownloadCount() error {
 	// Update download count.
-	if _, err := x.Exec("UPDATE `attachment` SET download_count=download_count+1 WHERE id=?", a.ID); err != nil {
+	if _, err := db.DefaultContext().Engine().Exec("UPDATE `attachment` SET download_count=download_count+1 WHERE id=?", a.ID); err != nil {
 		return fmt.Errorf("increase attachment count: %v", err)
 	}
 
@@ -81,10 +86,10 @@ func (a *Attachment) LinkedRepository() (*Repository, UnitType, error) {
 
 // GetAttachmentByID returns attachment by given id
 func GetAttachmentByID(id int64) (*Attachment, error) {
-	return getAttachmentByID(x, id)
+	return getAttachmentByID(db.DefaultContext().Engine(), id)
 }
 
-func getAttachmentByID(e Engine, id int64) (*Attachment, error) {
+func getAttachmentByID(e db.Engine, id int64) (*Attachment, error) {
 	attach := &Attachment{}
 	if has, err := e.ID(id).Get(attach); err != nil {
 		return nil, err
@@ -94,7 +99,7 @@ func getAttachmentByID(e Engine, id int64) (*Attachment, error) {
 	return attach, nil
 }
 
-func getAttachmentByUUID(e Engine, uuid string) (*Attachment, error) {
+func getAttachmentByUUID(e db.Engine, uuid string) (*Attachment, error) {
 	attach := &Attachment{}
 	has, err := e.Where("uuid=?", uuid).Get(attach)
 	if err != nil {
@@ -106,11 +111,11 @@ func getAttachmentByUUID(e Engine, uuid string) (*Attachment, error) {
 }
 
 // GetAttachmentsByUUIDs returns attachment by given UUID list.
-func GetAttachmentsByUUIDs(ctx DBContext, uuids []string) ([]*Attachment, error) {
-	return getAttachmentsByUUIDs(ctx.e, uuids)
+func GetAttachmentsByUUIDs(ctx *db.Context, uuids []string) ([]*Attachment, error) {
+	return getAttachmentsByUUIDs(ctx.Engine(), uuids)
 }
 
-func getAttachmentsByUUIDs(e Engine, uuids []string) ([]*Attachment, error) {
+func getAttachmentsByUUIDs(e db.Engine, uuids []string) ([]*Attachment, error) {
 	if len(uuids) == 0 {
 		return []*Attachment{}, nil
 	}
@@ -122,41 +127,41 @@ func getAttachmentsByUUIDs(e Engine, uuids []string) ([]*Attachment, error) {
 
 // GetAttachmentByUUID returns attachment by given UUID.
 func GetAttachmentByUUID(uuid string) (*Attachment, error) {
-	return getAttachmentByUUID(x, uuid)
+	return getAttachmentByUUID(db.DefaultContext().Engine(), uuid)
 }
 
 // ExistAttachmentsByUUID returns true if attachment is exist by given UUID
 func ExistAttachmentsByUUID(uuid string) (bool, error) {
-	return x.Where("`uuid`=?", uuid).Exist(new(Attachment))
+	return db.DefaultContext().Engine().Where("`uuid`=?", uuid).Exist(new(Attachment))
 }
 
 // GetAttachmentByReleaseIDFileName returns attachment by given releaseId and fileName.
 func GetAttachmentByReleaseIDFileName(releaseID int64, fileName string) (*Attachment, error) {
-	return getAttachmentByReleaseIDFileName(x, releaseID, fileName)
+	return getAttachmentByReleaseIDFileName(db.DefaultContext().Engine(), releaseID, fileName)
 }
 
-func getAttachmentsByIssueID(e Engine, issueID int64) ([]*Attachment, error) {
+func getAttachmentsByIssueID(e db.Engine, issueID int64) ([]*Attachment, error) {
 	attachments := make([]*Attachment, 0, 10)
 	return attachments, e.Where("issue_id = ? AND comment_id = 0", issueID).Find(&attachments)
 }
 
 // GetAttachmentsByIssueID returns all attachments of an issue.
 func GetAttachmentsByIssueID(issueID int64) ([]*Attachment, error) {
-	return getAttachmentsByIssueID(x, issueID)
+	return getAttachmentsByIssueID(db.DefaultContext().Engine(), issueID)
 }
 
 // GetAttachmentsByCommentID returns all attachments if comment by given ID.
 func GetAttachmentsByCommentID(commentID int64) ([]*Attachment, error) {
-	return getAttachmentsByCommentID(x, commentID)
+	return getAttachmentsByCommentID(db.DefaultContext().Engine(), commentID)
 }
 
-func getAttachmentsByCommentID(e Engine, commentID int64) ([]*Attachment, error) {
+func getAttachmentsByCommentID(e db.Engine, commentID int64) ([]*Attachment, error) {
 	attachments := make([]*Attachment, 0, 10)
 	return attachments, e.Where("comment_id=?", commentID).Find(&attachments)
 }
 
 // getAttachmentByReleaseIDFileName return a file based on the the following infos:
-func getAttachmentByReleaseIDFileName(e Engine, releaseID int64, fileName string) (*Attachment, error) {
+func getAttachmentByReleaseIDFileName(e db.Engine, releaseID int64, fileName string) (*Attachment, error) {
 	attach := &Attachment{ReleaseID: releaseID, Name: fileName}
 	has, err := e.Get(attach)
 	if err != nil {
@@ -169,12 +174,12 @@ func getAttachmentByReleaseIDFileName(e Engine, releaseID int64, fileName string
 
 // DeleteAttachment deletes the given attachment and optionally the associated file.
 func DeleteAttachment(a *Attachment, remove bool) error {
-	_, err := DeleteAttachments(DefaultDBContext(), []*Attachment{a}, remove)
+	_, err := DeleteAttachments(db.DefaultContext(), []*Attachment{a}, remove)
 	return err
 }
 
 // DeleteAttachments deletes the given attachments and optionally the associated files.
-func DeleteAttachments(ctx DBContext, attachments []*Attachment, remove bool) (int, error) {
+func DeleteAttachments(ctx *db.Context, attachments []*Attachment, remove bool) (int, error) {
 	if len(attachments) == 0 {
 		return 0, nil
 	}
@@ -184,7 +189,7 @@ func DeleteAttachments(ctx DBContext, attachments []*Attachment, remove bool) (i
 		ids = append(ids, a.ID)
 	}
 
-	cnt, err := ctx.e.In("id", ids).NoAutoCondition().Delete(attachments[0])
+	cnt, err := ctx.Engine().In("id", ids).NoAutoCondition().Delete(attachments[0])
 	if err != nil {
 		return 0, err
 	}
@@ -206,7 +211,7 @@ func DeleteAttachmentsByIssue(issueID int64, remove bool) (int, error) {
 		return 0, err
 	}
 
-	return DeleteAttachments(DefaultDBContext(), attachments, remove)
+	return DeleteAttachments(db.DefaultContext(), attachments, remove)
 }
 
 // DeleteAttachmentsByComment deletes all attachments associated with the given comment.
@@ -216,24 +221,24 @@ func DeleteAttachmentsByComment(commentID int64, remove bool) (int, error) {
 		return 0, err
 	}
 
-	return DeleteAttachments(DefaultDBContext(), attachments, remove)
+	return DeleteAttachments(db.DefaultContext(), attachments, remove)
 }
 
 // UpdateAttachment updates the given attachment in database
 func UpdateAttachment(atta *Attachment) error {
-	return updateAttachment(x, atta)
+	return updateAttachment(db.DefaultContext().Engine(), atta)
 }
 
 // UpdateAttachmentByUUID Updates attachment via uuid
-func UpdateAttachmentByUUID(ctx DBContext, attach *Attachment, cols ...string) error {
+func UpdateAttachmentByUUID(ctx *db.Context, attach *Attachment, cols ...string) error {
 	if attach.UUID == "" {
 		return fmt.Errorf("Attachement uuid should not blank")
 	}
-	_, err := ctx.e.Where("uuid=?", attach.UUID).Cols(cols...).Update(attach)
+	_, err := ctx.Engine().Where("uuid=?", attach.UUID).Cols(cols...).Update(attach)
 	return err
 }
 
-func updateAttachment(e Engine, atta *Attachment) error {
+func updateAttachment(e db.Engine, atta *Attachment) error {
 	var sess *xorm.Session
 	if atta.ID != 0 && atta.UUID == "" {
 		sess = e.ID(atta.ID)
@@ -247,7 +252,7 @@ func updateAttachment(e Engine, atta *Attachment) error {
 
 // DeleteAttachmentsByRelease deletes all attachments associated with the given release.
 func DeleteAttachmentsByRelease(releaseID int64) error {
-	_, err := x.Where("release_id = ?", releaseID).Delete(&Attachment{})
+	_, err := db.DefaultContext().Engine().Where("release_id = ?", releaseID).Delete(&Attachment{})
 	return err
 }
 
@@ -257,7 +262,7 @@ func IterateAttachment(f func(attach *Attachment) error) error {
 	const batchSize = 100
 	for {
 		attachments := make([]*Attachment, 0, batchSize)
-		if err := x.Limit(batchSize, start).Find(&attachments); err != nil {
+		if err := db.DefaultContext().Engine().Limit(batchSize, start).Find(&attachments); err != nil {
 			return err
 		}
 		if len(attachments) == 0 {
@@ -275,13 +280,13 @@ func IterateAttachment(f func(attach *Attachment) error) error {
 
 // CountOrphanedAttachments returns the number of bad attachments
 func CountOrphanedAttachments() (int64, error) {
-	return x.Where("(issue_id > 0 and issue_id not in (select id from issue)) or (release_id > 0 and release_id not in (select id from `release`))").
+	return db.DefaultContext().Engine().Where("(issue_id > 0 and issue_id not in (select id from issue)) or (release_id > 0 and release_id not in (select id from `release`))").
 		Count(new(Attachment))
 }
 
 // DeleteOrphanedAttachments delete all bad attachments
 func DeleteOrphanedAttachments() error {
-	_, err := x.Where("(issue_id > 0 and issue_id not in (select id from issue)) or (release_id > 0 and release_id not in (select id from `release`))").
+	_, err := db.DefaultContext().Engine().Where("(issue_id > 0 and issue_id not in (select id from issue)) or (release_id > 0 and release_id not in (select id from `release`))").
 		Delete(new(Attachment))
 	return err
 }
diff --git a/models/attachment_test.go b/models/attachment_test.go
index 4f6eb0a5e..3e8e78a0a 100644
--- a/models/attachment_test.go
+++ b/models/attachment_test.go
@@ -7,11 +7,12 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestIncreaseDownloadCount(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	attachment, err := GetAttachmentByUUID("a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11")
 	assert.NoError(t, err)
@@ -27,7 +28,7 @@ func TestIncreaseDownloadCount(t *testing.T) {
 }
 
 func TestGetByCommentOrIssueID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// count of attachments from issue ID
 	attachments, err := GetAttachmentsByIssueID(1)
@@ -40,7 +41,7 @@ func TestGetByCommentOrIssueID(t *testing.T) {
 }
 
 func TestDeleteAttachments(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	count, err := DeleteAttachmentsByIssue(4, false)
 	assert.NoError(t, err)
@@ -60,7 +61,7 @@ func TestDeleteAttachments(t *testing.T) {
 }
 
 func TestGetAttachmentByID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	attach, err := GetAttachmentByID(1)
 	assert.NoError(t, err)
@@ -76,7 +77,7 @@ func TestAttachment_DownloadURL(t *testing.T) {
 }
 
 func TestUpdateAttachment(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	attach, err := GetAttachmentByID(1)
 	assert.NoError(t, err)
@@ -85,13 +86,13 @@ func TestUpdateAttachment(t *testing.T) {
 	attach.Name = "new_name"
 	assert.NoError(t, UpdateAttachment(attach))
 
-	AssertExistsAndLoadBean(t, &Attachment{Name: "new_name"})
+	db.AssertExistsAndLoadBean(t, &Attachment{Name: "new_name"})
 }
 
 func TestGetAttachmentsByUUIDs(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	attachList, err := GetAttachmentsByUUIDs(DefaultDBContext(), []string{"a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11", "a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a17", "not-existing-uuid"})
+	attachList, err := GetAttachmentsByUUIDs(db.DefaultContext(), []string{"a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11", "a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a17", "not-existing-uuid"})
 	assert.NoError(t, err)
 	assert.Len(t, attachList, 2)
 	assert.Equal(t, "a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11", attachList[0].UUID)
@@ -101,7 +102,7 @@ func TestGetAttachmentsByUUIDs(t *testing.T) {
 }
 
 func TestLinkedRepository(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	testCases := []struct {
 		name             string
 		attachID         int64
diff --git a/models/avatar.go b/models/avatar.go
index b4c078f8c..e81b87666 100644
--- a/models/avatar.go
+++ b/models/avatar.go
@@ -12,6 +12,7 @@ import (
 	"strconv"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/cache"
 	"code.gitea.io/gitea/modules/log"
@@ -24,6 +25,10 @@ type EmailHash struct {
 	Email string `xorm:"UNIQUE NOT NULL"`
 }
 
+func init() {
+	db.RegisterModel(new(EmailHash))
+}
+
 // DefaultAvatarLink the default avatar link
 func DefaultAvatarLink() string {
 	u, err := url.Parse(setting.AppSubURL)
@@ -59,7 +64,7 @@ func GetEmailForHash(md5Sum string) (string, error) {
 			Hash: strings.ToLower(strings.TrimSpace(md5Sum)),
 		}
 
-		_, err := x.Get(&emailHash)
+		_, err := db.DefaultContext().Engine().Get(&emailHash)
 		return emailHash.Email, err
 	})
 }
@@ -90,19 +95,15 @@ func HashedAvatarLink(email string, size int) string {
 			Hash:  sum,
 		}
 		// OK we're going to open a session just because I think that that might hide away any problems with postgres reporting errors
-		sess := x.NewSession()
-		defer sess.Close()
-		if err := sess.Begin(); err != nil {
-			// we don't care about any DB problem just return the lowerEmail
-			return lowerEmail, nil
-		}
-		has, err := sess.Where("email = ? AND hash = ?", emailHash.Email, emailHash.Hash).Get(new(EmailHash))
-		if has || err != nil {
-			// Seriously we don't care about any DB problems just return the lowerEmail - we expect the transaction to fail most of the time
-			return lowerEmail, nil
-		}
-		_, _ = sess.Insert(emailHash)
-		if err := sess.Commit(); err != nil {
+		if err := db.WithTx(func(ctx *db.Context) error {
+			has, err := ctx.Engine().Where("email = ? AND hash = ?", emailHash.Email, emailHash.Hash).Get(new(EmailHash))
+			if has || err != nil {
+				// Seriously we don't care about any DB problems just return the lowerEmail - we expect the transaction to fail most of the time
+				return nil
+			}
+			_, _ = ctx.Engine().Insert(emailHash)
+			return nil
+		}); err != nil {
 			// Seriously we don't care about any DB problems just return the lowerEmail - we expect the transaction to fail most of the time
 			return lowerEmail, nil
 		}
diff --git a/models/branches.go b/models/branches.go
index 880cd42fe..617dfe488 100644
--- a/models/branches.go
+++ b/models/branches.go
@@ -10,6 +10,7 @@ import (
 	"strings"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/timeutil"
@@ -49,6 +50,11 @@ type ProtectedBranch struct {
 	UpdatedUnix timeutil.TimeStamp `xorm:"updated"`
 }
 
+func init() {
+	db.RegisterModel(new(ProtectedBranch))
+	db.RegisterModel(new(DeletedBranch))
+}
+
 // IsProtected returns if the branch is protected
 func (protectBranch *ProtectedBranch) IsProtected() bool {
 	return protectBranch.ID > 0
@@ -116,10 +122,10 @@ func (protectBranch *ProtectedBranch) IsUserMergeWhitelisted(userID int64, permi
 
 // IsUserOfficialReviewer check if user is official reviewer for the branch (counts towards required approvals)
 func (protectBranch *ProtectedBranch) IsUserOfficialReviewer(user *User) (bool, error) {
-	return protectBranch.isUserOfficialReviewer(x, user)
+	return protectBranch.isUserOfficialReviewer(db.DefaultContext().Engine(), user)
 }
 
-func (protectBranch *ProtectedBranch) isUserOfficialReviewer(e Engine, user *User) (bool, error) {
+func (protectBranch *ProtectedBranch) isUserOfficialReviewer(e db.Engine, user *User) (bool, error) {
 	repo, err := getRepositoryByID(e, protectBranch.RepoID)
 	if err != nil {
 		return false, err
@@ -156,7 +162,7 @@ func (protectBranch *ProtectedBranch) HasEnoughApprovals(pr *PullRequest) bool {
 
 // GetGrantedApprovalsCount returns the number of granted approvals for pr. A granted approval must be authored by a user in an approval whitelist.
 func (protectBranch *ProtectedBranch) GetGrantedApprovalsCount(pr *PullRequest) int64 {
-	sess := x.Where("issue_id = ?", pr.IssueID).
+	sess := db.DefaultContext().Engine().Where("issue_id = ?", pr.IssueID).
 		And("type = ?", ReviewTypeApprove).
 		And("official = ?", true).
 		And("dismissed = ?", false)
@@ -177,7 +183,7 @@ func (protectBranch *ProtectedBranch) MergeBlockedByRejectedReview(pr *PullReque
 	if !protectBranch.BlockOnRejectedReviews {
 		return false
 	}
-	rejectExist, err := x.Where("issue_id = ?", pr.IssueID).
+	rejectExist, err := db.DefaultContext().Engine().Where("issue_id = ?", pr.IssueID).
 		And("type = ?", ReviewTypeReject).
 		And("official = ?", true).
 		And("dismissed = ?", false).
@@ -196,7 +202,7 @@ func (protectBranch *ProtectedBranch) MergeBlockedByOfficialReviewRequests(pr *P
 	if !protectBranch.BlockOnOfficialReviewRequests {
 		return false
 	}
-	has, err := x.Where("issue_id = ?", pr.IssueID).
+	has, err := db.DefaultContext().Engine().Where("issue_id = ?", pr.IssueID).
 		And("type = ?", ReviewTypeRequest).
 		And("official = ?", true).
 		Exist(new(Review))
@@ -294,10 +300,10 @@ func (protectBranch *ProtectedBranch) IsUnprotectedFile(patterns []glob.Glob, pa
 
 // GetProtectedBranchBy getting protected branch by ID/Name
 func GetProtectedBranchBy(repoID int64, branchName string) (*ProtectedBranch, error) {
-	return getProtectedBranchBy(x, repoID, branchName)
+	return getProtectedBranchBy(db.DefaultContext().Engine(), repoID, branchName)
 }
 
-func getProtectedBranchBy(e Engine, repoID int64, branchName string) (*ProtectedBranch, error) {
+func getProtectedBranchBy(e db.Engine, repoID int64, branchName string) (*ProtectedBranch, error) {
 	rel := &ProtectedBranch{RepoID: repoID, BranchName: branchName}
 	has, err := e.Get(rel)
 	if err != nil {
@@ -369,13 +375,13 @@ func UpdateProtectBranch(repo *Repository, protectBranch *ProtectedBranch, opts
 
 	// Make sure protectBranch.ID is not 0 for whitelists
 	if protectBranch.ID == 0 {
-		if _, err = x.Insert(protectBranch); err != nil {
+		if _, err = db.DefaultContext().Engine().Insert(protectBranch); err != nil {
 			return fmt.Errorf("Insert: %v", err)
 		}
 		return nil
 	}
 
-	if _, err = x.ID(protectBranch.ID).AllCols().Update(protectBranch); err != nil {
+	if _, err = db.DefaultContext().Engine().ID(protectBranch.ID).AllCols().Update(protectBranch); err != nil {
 		return fmt.Errorf("Update: %v", err)
 	}
 
@@ -385,7 +391,7 @@ func UpdateProtectBranch(repo *Repository, protectBranch *ProtectedBranch, opts
 // GetProtectedBranches get all protected branches
 func (repo *Repository) GetProtectedBranches() ([]*ProtectedBranch, error) {
 	protectedBranches := make([]*ProtectedBranch, 0)
-	return protectedBranches, x.Find(&protectedBranches, &ProtectedBranch{RepoID: repo.ID})
+	return protectedBranches, db.DefaultContext().Engine().Find(&protectedBranches, &ProtectedBranch{RepoID: repo.ID})
 }
 
 // GetBranchProtection get the branch protection of a branch
@@ -400,7 +406,7 @@ func (repo *Repository) IsProtectedBranch(branchName string) (bool, error) {
 		BranchName: branchName,
 	}
 
-	has, err := x.Exist(protectedBranch)
+	has, err := db.DefaultContext().Engine().Exist(protectedBranch)
 	if err != nil {
 		return true, err
 	}
@@ -487,19 +493,13 @@ func (repo *Repository) DeleteProtectedBranch(id int64) (err error) {
 		ID:     id,
 	}
 
-	sess := x.NewSession()
-	defer sess.Close()
-	if err = sess.Begin(); err != nil {
-		return err
-	}
-
-	if affected, err := sess.Delete(protectedBranch); err != nil {
+	if affected, err := db.DefaultContext().Engine().Delete(protectedBranch); err != nil {
 		return err
 	} else if affected != 1 {
 		return fmt.Errorf("delete protected branch ID(%v) failed", id)
 	}
 
-	return sess.Commit()
+	return nil
 }
 
 // DeletedBranch struct
@@ -522,29 +522,20 @@ func (repo *Repository) AddDeletedBranch(branchName, commit string, deletedByID
 		DeletedByID: deletedByID,
 	}
 
-	sess := x.NewSession()
-	defer sess.Close()
-	if err := sess.Begin(); err != nil {
-		return err
-	}
-
-	if _, err := sess.InsertOne(deletedBranch); err != nil {
-		return err
-	}
-
-	return sess.Commit()
+	_, err := db.DefaultContext().Engine().InsertOne(deletedBranch)
+	return err
 }
 
 // GetDeletedBranches returns all the deleted branches
 func (repo *Repository) GetDeletedBranches() ([]*DeletedBranch, error) {
 	deletedBranches := make([]*DeletedBranch, 0)
-	return deletedBranches, x.Where("repo_id = ?", repo.ID).Desc("deleted_unix").Find(&deletedBranches)
+	return deletedBranches, db.DefaultContext().Engine().Where("repo_id = ?", repo.ID).Desc("deleted_unix").Find(&deletedBranches)
 }
 
 // GetDeletedBranchByID get a deleted branch by its ID
 func (repo *Repository) GetDeletedBranchByID(id int64) (*DeletedBranch, error) {
 	deletedBranch := &DeletedBranch{}
-	has, err := x.ID(id).Get(deletedBranch)
+	has, err := db.DefaultContext().Engine().ID(id).Get(deletedBranch)
 	if err != nil {
 		return nil, err
 	}
@@ -561,19 +552,13 @@ func (repo *Repository) RemoveDeletedBranch(id int64) (err error) {
 		ID:     id,
 	}
 
-	sess := x.NewSession()
-	defer sess.Close()
-	if err = sess.Begin(); err != nil {
-		return err
-	}
-
-	if affected, err := sess.Delete(deletedBranch); err != nil {
+	if affected, err := db.DefaultContext().Engine().Delete(deletedBranch); err != nil {
 		return err
 	} else if affected != 1 {
 		return fmt.Errorf("remove deleted branch ID(%v) failed", id)
 	}
 
-	return sess.Commit()
+	return nil
 }
 
 // LoadUser loads the user that deleted the branch
@@ -588,7 +573,7 @@ func (deletedBranch *DeletedBranch) LoadUser() {
 
 // RemoveDeletedBranch removes all deleted branches
 func RemoveDeletedBranch(repoID int64, branch string) error {
-	_, err := x.Where("repo_id=? AND name=?", repoID, branch).Delete(new(DeletedBranch))
+	_, err := db.DefaultContext().Engine().Where("repo_id=? AND name=?", repoID, branch).Delete(new(DeletedBranch))
 	return err
 }
 
@@ -598,7 +583,7 @@ func RemoveOldDeletedBranches(ctx context.Context, olderThan time.Duration) {
 	log.Trace("Doing: DeletedBranchesCleanup")
 
 	deleteBefore := time.Now().Add(-olderThan)
-	_, err := x.Where("deleted_unix < ?", deleteBefore.Unix()).Delete(new(DeletedBranch))
+	_, err := db.DefaultContext().Engine().Where("deleted_unix < ?", deleteBefore.Unix()).Delete(new(DeletedBranch))
 	if err != nil {
 		log.Error("DeletedBranchesCleanup: %v", err)
 	}
diff --git a/models/branches_test.go b/models/branches_test.go
index b7984331e..02a9e81a7 100644
--- a/models/branches_test.go
+++ b/models/branches_test.go
@@ -7,21 +7,22 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestAddDeletedBranch(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
-	firstBranch := AssertExistsAndLoadBean(t, &DeletedBranch{ID: 1}).(*DeletedBranch)
+	assert.NoError(t, db.PrepareTestDatabase())
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	firstBranch := db.AssertExistsAndLoadBean(t, &DeletedBranch{ID: 1}).(*DeletedBranch)
 
 	assert.Error(t, repo.AddDeletedBranch(firstBranch.Name, firstBranch.Commit, firstBranch.DeletedByID))
 	assert.NoError(t, repo.AddDeletedBranch("test", "5655464564554545466464656", int64(1)))
 }
 
 func TestGetDeletedBranches(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	assert.NoError(t, db.PrepareTestDatabase())
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
 
 	branches, err := repo.GetDeletedBranches()
 	assert.NoError(t, err)
@@ -29,17 +30,17 @@ func TestGetDeletedBranches(t *testing.T) {
 }
 
 func TestGetDeletedBranch(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	firstBranch := AssertExistsAndLoadBean(t, &DeletedBranch{ID: 1}).(*DeletedBranch)
+	assert.NoError(t, db.PrepareTestDatabase())
+	firstBranch := db.AssertExistsAndLoadBean(t, &DeletedBranch{ID: 1}).(*DeletedBranch)
 
 	assert.NotNil(t, getDeletedBranch(t, firstBranch))
 }
 
 func TestDeletedBranchLoadUser(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	firstBranch := AssertExistsAndLoadBean(t, &DeletedBranch{ID: 1}).(*DeletedBranch)
-	secondBranch := AssertExistsAndLoadBean(t, &DeletedBranch{ID: 2}).(*DeletedBranch)
+	firstBranch := db.AssertExistsAndLoadBean(t, &DeletedBranch{ID: 1}).(*DeletedBranch)
+	secondBranch := db.AssertExistsAndLoadBean(t, &DeletedBranch{ID: 2}).(*DeletedBranch)
 
 	branch := getDeletedBranch(t, firstBranch)
 	assert.Nil(t, branch.DeletedBy)
@@ -55,19 +56,19 @@ func TestDeletedBranchLoadUser(t *testing.T) {
 }
 
 func TestRemoveDeletedBranch(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	assert.NoError(t, db.PrepareTestDatabase())
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
 
-	firstBranch := AssertExistsAndLoadBean(t, &DeletedBranch{ID: 1}).(*DeletedBranch)
+	firstBranch := db.AssertExistsAndLoadBean(t, &DeletedBranch{ID: 1}).(*DeletedBranch)
 
 	err := repo.RemoveDeletedBranch(1)
 	assert.NoError(t, err)
-	AssertNotExistsBean(t, firstBranch)
-	AssertExistsAndLoadBean(t, &DeletedBranch{ID: 2})
+	db.AssertNotExistsBean(t, firstBranch)
+	db.AssertExistsAndLoadBean(t, &DeletedBranch{ID: 2})
 }
 
 func getDeletedBranch(t *testing.T, branch *DeletedBranch) *DeletedBranch {
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
 
 	deletedBranch, err := repo.GetDeletedBranchByID(branch.ID)
 	assert.NoError(t, err)
diff --git a/models/commit_status.go b/models/commit_status.go
index 5926930ec..f3639e819 100644
--- a/models/commit_status.go
+++ b/models/commit_status.go
@@ -10,6 +10,7 @@ import (
 	"strings"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
@@ -37,7 +38,11 @@ type CommitStatus struct {
 	UpdatedUnix timeutil.TimeStamp `xorm:"INDEX updated"`
 }
 
-func (status *CommitStatus) loadAttributes(e Engine) (err error) {
+func init() {
+	db.RegisterModel(new(CommitStatus))
+}
+
+func (status *CommitStatus) loadAttributes(e db.Engine) (err error) {
 	if status.Repo == nil {
 		status.Repo, err = getRepositoryByID(e, status.RepoID)
 		if err != nil {
@@ -55,7 +60,7 @@ func (status *CommitStatus) loadAttributes(e Engine) (err error) {
 
 // APIURL returns the absolute APIURL to this commit-status.
 func (status *CommitStatus) APIURL() string {
-	_ = status.loadAttributes(x)
+	_ = status.loadAttributes(db.DefaultContext().Engine())
 	return fmt.Sprintf("%sapi/v1/repos/%s/statuses/%s",
 		setting.AppURL, status.Repo.FullName(), status.SHA)
 }
@@ -112,7 +117,7 @@ func GetCommitStatuses(repo *Repository, sha string, opts *CommitStatusOptions)
 }
 
 func listCommitStatusesStatement(repo *Repository, sha string, opts *CommitStatusOptions) *xorm.Session {
-	sess := x.Where("repo_id = ?", repo.ID).And("sha = ?", sha)
+	sess := db.DefaultContext().Engine().Where("repo_id = ?", repo.ID).And("sha = ?", sha)
 	switch opts.State {
 	case "pending", "success", "error", "failure", "warning":
 		sess.And("state = ?", opts.State)
@@ -139,10 +144,10 @@ func sortCommitStatusesSession(sess *xorm.Session, sortType string) {
 
 // GetLatestCommitStatus returns all statuses with a unique context for a given commit.
 func GetLatestCommitStatus(repoID int64, sha string, listOptions ListOptions) ([]*CommitStatus, error) {
-	return getLatestCommitStatus(x, repoID, sha, listOptions)
+	return getLatestCommitStatus(db.DefaultContext().Engine(), repoID, sha, listOptions)
 }
 
-func getLatestCommitStatus(e Engine, repoID int64, sha string, listOptions ListOptions) ([]*CommitStatus, error) {
+func getLatestCommitStatus(e db.Engine, repoID int64, sha string, listOptions ListOptions) ([]*CommitStatus, error) {
 	ids := make([]int64, 0, 10)
 	sess := e.Table(&CommitStatus{}).
 		Where("repo_id = ?", repoID).And("sha = ?", sha).
@@ -166,7 +171,7 @@ func getLatestCommitStatus(e Engine, repoID int64, sha string, listOptions ListO
 func FindRepoRecentCommitStatusContexts(repoID int64, before time.Duration) ([]string, error) {
 	start := timeutil.TimeStampNow().AddDuration(-before)
 	ids := make([]int64, 0, 10)
-	if err := x.Table("commit_status").
+	if err := db.DefaultContext().Engine().Table("commit_status").
 		Where("repo_id = ?", repoID).
 		And("updated_unix >= ?", start).
 		Select("max( id ) as id").
@@ -179,7 +184,7 @@ func FindRepoRecentCommitStatusContexts(repoID int64, before time.Duration) ([]s
 	if len(ids) == 0 {
 		return contexts, nil
 	}
-	return contexts, x.Select("context").Table("commit_status").In("id", ids).Find(&contexts)
+	return contexts, db.DefaultContext().Engine().Select("context").Table("commit_status").In("id", ids).Find(&contexts)
 }
 
 // NewCommitStatusOptions holds options for creating a CommitStatus
@@ -201,12 +206,11 @@ func NewCommitStatus(opts NewCommitStatusOptions) error {
 		return fmt.Errorf("NewCommitStatus[%s, %s]: no user specified", repoPath, opts.SHA)
 	}
 
-	sess := x.NewSession()
-	defer sess.Close()
-
-	if err := sess.Begin(); err != nil {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
 		return fmt.Errorf("NewCommitStatus[repo_id: %d, user_id: %d, sha: %s]: %v", opts.Repo.ID, opts.Creator.ID, opts.SHA, err)
 	}
+	defer committer.Close()
 
 	opts.CommitStatus.Description = strings.TrimSpace(opts.CommitStatus.Description)
 	opts.CommitStatus.Context = strings.TrimSpace(opts.CommitStatus.Context)
@@ -221,11 +225,8 @@ func NewCommitStatus(opts NewCommitStatusOptions) error {
 		SHA:    opts.SHA,
 		RepoID: opts.Repo.ID,
 	}
-	has, err := sess.Desc("index").Limit(1).Get(lastCommitStatus)
+	has, err := ctx.Engine().Desc("index").Limit(1).Get(lastCommitStatus)
 	if err != nil {
-		if err := sess.Rollback(); err != nil {
-			log.Error("NewCommitStatus: sess.Rollback: %v", err)
-		}
 		return fmt.Errorf("NewCommitStatus[%s, %s]: %v", repoPath, opts.SHA, err)
 	}
 	if has {
@@ -238,14 +239,11 @@ func NewCommitStatus(opts NewCommitStatusOptions) error {
 	opts.CommitStatus.ContextHash = hashCommitStatusContext(opts.CommitStatus.Context)
 
 	// Insert new CommitStatus
-	if _, err = sess.Insert(opts.CommitStatus); err != nil {
-		if err := sess.Rollback(); err != nil {
-			log.Error("Insert CommitStatus: sess.Rollback: %v", err)
-		}
+	if _, err = ctx.Engine().Insert(opts.CommitStatus); err != nil {
 		return fmt.Errorf("Insert CommitStatus[%s, %s]: %v", repoPath, opts.SHA, err)
 	}
 
-	return sess.Commit()
+	return committer.Commit()
 }
 
 // SignCommitWithStatuses represents a commit with validation of signature and status state.
diff --git a/models/commit_status_test.go b/models/commit_status_test.go
index 57b97f660..0d8dbf264 100644
--- a/models/commit_status_test.go
+++ b/models/commit_status_test.go
@@ -7,14 +7,15 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/structs"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestGetCommitStatuses(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	repo1 := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	repo1 := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
 
 	sha1 := "1234123412341234123412341234123412341234"
 
diff --git a/models/consistency.go b/models/consistency.go
index f037b0515..cc02e32de 100644
--- a/models/consistency.go
+++ b/models/consistency.go
@@ -5,13 +5,11 @@
 package models
 
 import (
-	"fmt"
 	"reflect"
-	"regexp"
 	"strings"
 	"testing"
 
-	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 	"xorm.io/builder"
 )
@@ -43,7 +41,7 @@ func CheckConsistencyFor(t *testing.T, beansToCheck ...interface{}) {
 		ptrToSliceValue := reflect.New(sliceType)
 		ptrToSliceValue.Elem().Set(sliceValue)
 
-		assert.NoError(t, x.Table(bean).Find(ptrToSliceValue.Interface()))
+		assert.NoError(t, db.DefaultContext().Engine().Table(bean).Find(ptrToSliceValue.Interface()))
 		sliceValue = ptrToSliceValue.Elem()
 
 		for i := 0; i < sliceValue.Len(); i++ {
@@ -60,7 +58,7 @@ func CheckConsistencyFor(t *testing.T, beansToCheck ...interface{}) {
 }
 
 // getCount get the count of database entries matching bean
-func getCount(t *testing.T, e Engine, bean interface{}) int64 {
+func getCount(t *testing.T, e db.Engine, bean interface{}) int64 {
 	count, err := e.Count(bean)
 	assert.NoError(t, err)
 	return count
@@ -68,7 +66,7 @@ func getCount(t *testing.T, e Engine, bean interface{}) int64 {
 
 // assertCount test the count of database entries matching bean
 func assertCount(t *testing.T, bean interface{}, expected int) {
-	assert.EqualValues(t, expected, getCount(t, x, bean),
+	assert.EqualValues(t, expected, getCount(t, db.DefaultContext().Engine(), bean),
 		"Failed consistency test, the counted bean (of type %T) was %+v", bean, bean)
 }
 
@@ -91,46 +89,46 @@ func (repo *Repository) checkForConsistency(t *testing.T) {
 	assertCount(t, &Milestone{RepoID: repo.ID}, repo.NumMilestones)
 	assertCount(t, &Repository{ForkID: repo.ID}, repo.NumForks)
 	if repo.IsFork {
-		AssertExistsAndLoadBean(t, &Repository{ID: repo.ForkID})
+		db.AssertExistsAndLoadBean(t, &Repository{ID: repo.ForkID})
 	}
 
-	actual := getCount(t, x.Where("Mode<>?", RepoWatchModeDont), &Watch{RepoID: repo.ID})
+	actual := getCount(t, db.DefaultContext().Engine().Where("Mode<>?", RepoWatchModeDont), &Watch{RepoID: repo.ID})
 	assert.EqualValues(t, repo.NumWatches, actual,
 		"Unexpected number of watches for repo %+v", repo)
 
-	actual = getCount(t, x.Where("is_pull=?", false), &Issue{RepoID: repo.ID})
+	actual = getCount(t, db.DefaultContext().Engine().Where("is_pull=?", false), &Issue{RepoID: repo.ID})
 	assert.EqualValues(t, repo.NumIssues, actual,
 		"Unexpected number of issues for repo %+v", repo)
 
-	actual = getCount(t, x.Where("is_pull=? AND is_closed=?", false, true), &Issue{RepoID: repo.ID})
+	actual = getCount(t, db.DefaultContext().Engine().Where("is_pull=? AND is_closed=?", false, true), &Issue{RepoID: repo.ID})
 	assert.EqualValues(t, repo.NumClosedIssues, actual,
 		"Unexpected number of closed issues for repo %+v", repo)
 
-	actual = getCount(t, x.Where("is_pull=?", true), &Issue{RepoID: repo.ID})
+	actual = getCount(t, db.DefaultContext().Engine().Where("is_pull=?", true), &Issue{RepoID: repo.ID})
 	assert.EqualValues(t, repo.NumPulls, actual,
 		"Unexpected number of pulls for repo %+v", repo)
 
-	actual = getCount(t, x.Where("is_pull=? AND is_closed=?", true, true), &Issue{RepoID: repo.ID})
+	actual = getCount(t, db.DefaultContext().Engine().Where("is_pull=? AND is_closed=?", true, true), &Issue{RepoID: repo.ID})
 	assert.EqualValues(t, repo.NumClosedPulls, actual,
 		"Unexpected number of closed pulls for repo %+v", repo)
 
-	actual = getCount(t, x.Where("is_closed=?", true), &Milestone{RepoID: repo.ID})
+	actual = getCount(t, db.DefaultContext().Engine().Where("is_closed=?", true), &Milestone{RepoID: repo.ID})
 	assert.EqualValues(t, repo.NumClosedMilestones, actual,
 		"Unexpected number of closed milestones for repo %+v", repo)
 }
 
 func (issue *Issue) checkForConsistency(t *testing.T) {
-	actual := getCount(t, x.Where("type=?", CommentTypeComment), &Comment{IssueID: issue.ID})
+	actual := getCount(t, db.DefaultContext().Engine().Where("type=?", CommentTypeComment), &Comment{IssueID: issue.ID})
 	assert.EqualValues(t, issue.NumComments, actual,
 		"Unexpected number of comments for issue %+v", issue)
 	if issue.IsPull {
-		pr := AssertExistsAndLoadBean(t, &PullRequest{IssueID: issue.ID}).(*PullRequest)
+		pr := db.AssertExistsAndLoadBean(t, &PullRequest{IssueID: issue.ID}).(*PullRequest)
 		assert.EqualValues(t, pr.Index, issue.Index)
 	}
 }
 
 func (pr *PullRequest) checkForConsistency(t *testing.T) {
-	issue := AssertExistsAndLoadBean(t, &Issue{ID: pr.IssueID}).(*Issue)
+	issue := db.AssertExistsAndLoadBean(t, &Issue{ID: pr.IssueID}).(*Issue)
 	assert.True(t, issue.IsPull)
 	assert.EqualValues(t, issue.Index, pr.Index)
 }
@@ -138,7 +136,7 @@ func (pr *PullRequest) checkForConsistency(t *testing.T) {
 func (milestone *Milestone) checkForConsistency(t *testing.T) {
 	assertCount(t, &Issue{MilestoneID: milestone.ID}, milestone.NumIssues)
 
-	actual := getCount(t, x.Where("is_closed=?", true), &Issue{MilestoneID: milestone.ID})
+	actual := getCount(t, db.DefaultContext().Engine().Where("is_closed=?", true), &Issue{MilestoneID: milestone.ID})
 	assert.EqualValues(t, milestone.NumClosedIssues, actual,
 		"Unexpected number of closed issues for milestone %+v", milestone)
 
@@ -151,7 +149,7 @@ func (milestone *Milestone) checkForConsistency(t *testing.T) {
 
 func (label *Label) checkForConsistency(t *testing.T) {
 	issueLabels := make([]*IssueLabel, 0, 10)
-	assert.NoError(t, x.Find(&issueLabels, &IssueLabel{LabelID: label.ID}))
+	assert.NoError(t, db.DefaultContext().Engine().Find(&issueLabels, &IssueLabel{LabelID: label.ID}))
 	assert.EqualValues(t, label.NumIssues, len(issueLabels),
 		"Unexpected number of issue for label %+v", label)
 
@@ -162,7 +160,7 @@ func (label *Label) checkForConsistency(t *testing.T) {
 
 	expected := int64(0)
 	if len(issueIDs) > 0 {
-		expected = getCount(t, x.In("id", issueIDs).Where("is_closed=?", true), &Issue{})
+		expected = getCount(t, db.DefaultContext().Engine().In("id", issueIDs).Where("is_closed=?", true), &Issue{})
 	}
 	assert.EqualValues(t, expected, label.NumClosedIssues,
 		"Unexpected number of closed issues for label %+v", label)
@@ -174,18 +172,18 @@ func (team *Team) checkForConsistency(t *testing.T) {
 }
 
 func (action *Action) checkForConsistency(t *testing.T) {
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: action.RepoID}).(*Repository)
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: action.RepoID}).(*Repository)
 	assert.Equal(t, repo.IsPrivate, action.IsPrivate, "action: %+v", action)
 }
 
 // CountOrphanedLabels return count of labels witch are broken and not accessible via ui anymore
 func CountOrphanedLabels() (int64, error) {
-	noref, err := x.Table("label").Where("repo_id=? AND org_id=?", 0, 0).Count("label.id")
+	noref, err := db.DefaultContext().Engine().Table("label").Where("repo_id=? AND org_id=?", 0, 0).Count("label.id")
 	if err != nil {
 		return 0, err
 	}
 
-	norepo, err := x.Table("label").
+	norepo, err := db.DefaultContext().Engine().Table("label").
 		Where(builder.And(
 			builder.Gt{"repo_id": 0},
 			builder.NotIn("repo_id", builder.Select("id").From("repository")),
@@ -195,7 +193,7 @@ func CountOrphanedLabels() (int64, error) {
 		return 0, err
 	}
 
-	noorg, err := x.Table("label").
+	noorg, err := db.DefaultContext().Engine().Table("label").
 		Where(builder.And(
 			builder.Gt{"org_id": 0},
 			builder.NotIn("org_id", builder.Select("id").From("user")),
@@ -211,12 +209,12 @@ func CountOrphanedLabels() (int64, error) {
 // DeleteOrphanedLabels delete labels witch are broken and not accessible via ui anymore
 func DeleteOrphanedLabels() error {
 	// delete labels with no reference
-	if _, err := x.Table("label").Where("repo_id=? AND org_id=?", 0, 0).Delete(new(Label)); err != nil {
+	if _, err := db.DefaultContext().Engine().Table("label").Where("repo_id=? AND org_id=?", 0, 0).Delete(new(Label)); err != nil {
 		return err
 	}
 
 	// delete labels with none existing repos
-	if _, err := x.
+	if _, err := db.DefaultContext().Engine().
 		Where(builder.And(
 			builder.Gt{"repo_id": 0},
 			builder.NotIn("repo_id", builder.Select("id").From("repository")),
@@ -226,7 +224,7 @@ func DeleteOrphanedLabels() error {
 	}
 
 	// delete labels with none existing orgs
-	if _, err := x.
+	if _, err := db.DefaultContext().Engine().
 		Where(builder.And(
 			builder.Gt{"org_id": 0},
 			builder.NotIn("org_id", builder.Select("id").From("user")),
@@ -240,14 +238,14 @@ func DeleteOrphanedLabels() error {
 
 // CountOrphanedIssueLabels return count of IssueLabels witch have no label behind anymore
 func CountOrphanedIssueLabels() (int64, error) {
-	return x.Table("issue_label").
+	return db.DefaultContext().Engine().Table("issue_label").
 		NotIn("label_id", builder.Select("id").From("label")).
 		Count()
 }
 
 // DeleteOrphanedIssueLabels delete IssueLabels witch have no label behind anymore
 func DeleteOrphanedIssueLabels() error {
-	_, err := x.
+	_, err := db.DefaultContext().Engine().
 		NotIn("label_id", builder.Select("id").From("label")).
 		Delete(IssueLabel{})
 
@@ -256,7 +254,7 @@ func DeleteOrphanedIssueLabels() error {
 
 // CountOrphanedIssues count issues without a repo
 func CountOrphanedIssues() (int64, error) {
-	return x.Table("issue").
+	return db.DefaultContext().Engine().Table("issue").
 		Join("LEFT", "repository", "issue.repo_id=repository.id").
 		Where(builder.IsNull{"repository.id"}).
 		Count("id")
@@ -264,15 +262,15 @@ func CountOrphanedIssues() (int64, error) {
 
 // DeleteOrphanedIssues delete issues without a repo
 func DeleteOrphanedIssues() error {
-	sess := x.NewSession()
-	defer sess.Close()
-	if err := sess.Begin(); err != nil {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
 		return err
 	}
+	defer committer.Close()
 
 	var ids []int64
 
-	if err := sess.Table("issue").Distinct("issue.repo_id").
+	if err := ctx.Engine().Table("issue").Distinct("issue.repo_id").
 		Join("LEFT", "repository", "issue.repo_id=repository.id").
 		Where(builder.IsNull{"repository.id"}).GroupBy("issue.repo_id").
 		Find(&ids); err != nil {
@@ -281,27 +279,28 @@ func DeleteOrphanedIssues() error {
 
 	var attachmentPaths []string
 	for i := range ids {
-		paths, err := deleteIssuesByRepoID(sess, ids[i])
+		paths, err := deleteIssuesByRepoID(ctx.Engine(), ids[i])
 		if err != nil {
 			return err
 		}
 		attachmentPaths = append(attachmentPaths, paths...)
 	}
 
-	if err := sess.Commit(); err != nil {
+	if err := committer.Commit(); err != nil {
 		return err
 	}
+	committer.Close()
 
 	// Remove issue attachment files.
 	for i := range attachmentPaths {
-		removeAllWithNotice(x, "Delete issue attachment", attachmentPaths[i])
+		removeAllWithNotice(db.DefaultContext().Engine(), "Delete issue attachment", attachmentPaths[i])
 	}
 	return nil
 }
 
 // CountOrphanedObjects count subjects with have no existing refobject anymore
 func CountOrphanedObjects(subject, refobject, joinCond string) (int64, error) {
-	return x.Table("`"+subject+"`").
+	return db.DefaultContext().Engine().Table("`"+subject+"`").
 		Join("LEFT", refobject, joinCond).
 		Where(builder.IsNull{"`" + refobject + "`.id"}).
 		Count("id")
@@ -317,45 +316,45 @@ func DeleteOrphanedObjects(subject, refobject, joinCond string) error {
 	if err != nil {
 		return err
 	}
-	_, err = x.Exec(append([]interface{}{sql}, args...)...)
+	_, err = db.DefaultContext().Engine().Exec(append([]interface{}{sql}, args...)...)
 	return err
 }
 
 // CountNullArchivedRepository counts the number of repositories with is_archived is null
 func CountNullArchivedRepository() (int64, error) {
-	return x.Where(builder.IsNull{"is_archived"}).Count(new(Repository))
+	return db.DefaultContext().Engine().Where(builder.IsNull{"is_archived"}).Count(new(Repository))
 }
 
 // FixNullArchivedRepository sets is_archived to false where it is null
 func FixNullArchivedRepository() (int64, error) {
-	return x.Where(builder.IsNull{"is_archived"}).Cols("is_archived").NoAutoTime().Update(&Repository{
+	return db.DefaultContext().Engine().Where(builder.IsNull{"is_archived"}).Cols("is_archived").NoAutoTime().Update(&Repository{
 		IsArchived: false,
 	})
 }
 
 // CountWrongUserType count OrgUser who have wrong type
 func CountWrongUserType() (int64, error) {
-	return x.Where(builder.Eq{"type": 0}.And(builder.Neq{"num_teams": 0})).Count(new(User))
+	return db.DefaultContext().Engine().Where(builder.Eq{"type": 0}.And(builder.Neq{"num_teams": 0})).Count(new(User))
 }
 
 // FixWrongUserType fix OrgUser who have wrong type
 func FixWrongUserType() (int64, error) {
-	return x.Where(builder.Eq{"type": 0}.And(builder.Neq{"num_teams": 0})).Cols("type").NoAutoTime().Update(&User{Type: 1})
+	return db.DefaultContext().Engine().Where(builder.Eq{"type": 0}.And(builder.Neq{"num_teams": 0})).Cols("type").NoAutoTime().Update(&User{Type: 1})
 }
 
 // CountCommentTypeLabelWithEmptyLabel count label comments with empty label
 func CountCommentTypeLabelWithEmptyLabel() (int64, error) {
-	return x.Where(builder.Eq{"type": CommentTypeLabel, "label_id": 0}).Count(new(Comment))
+	return db.DefaultContext().Engine().Where(builder.Eq{"type": CommentTypeLabel, "label_id": 0}).Count(new(Comment))
 }
 
 // FixCommentTypeLabelWithEmptyLabel count label comments with empty label
 func FixCommentTypeLabelWithEmptyLabel() (int64, error) {
-	return x.Where(builder.Eq{"type": CommentTypeLabel, "label_id": 0}).Delete(new(Comment))
+	return db.DefaultContext().Engine().Where(builder.Eq{"type": CommentTypeLabel, "label_id": 0}).Delete(new(Comment))
 }
 
 // CountCommentTypeLabelWithOutsideLabels count label comments with outside label
 func CountCommentTypeLabelWithOutsideLabels() (int64, error) {
-	return x.Where("comment.type = ? AND ((label.org_id = 0 AND issue.repo_id != label.repo_id) OR (label.repo_id = 0 AND label.org_id != repository.owner_id))", CommentTypeLabel).
+	return db.DefaultContext().Engine().Where("comment.type = ? AND ((label.org_id = 0 AND issue.repo_id != label.repo_id) OR (label.repo_id = 0 AND label.org_id != repository.owner_id))", CommentTypeLabel).
 		Table("comment").
 		Join("inner", "label", "label.id = comment.label_id").
 		Join("inner", "issue", "issue.id = comment.issue_id ").
@@ -365,7 +364,7 @@ func CountCommentTypeLabelWithOutsideLabels() (int64, error) {
 
 // FixCommentTypeLabelWithOutsideLabels count label comments with outside label
 func FixCommentTypeLabelWithOutsideLabels() (int64, error) {
-	res, err := x.Exec(`DELETE FROM comment WHERE comment.id IN (
+	res, err := db.DefaultContext().Engine().Exec(`DELETE FROM comment WHERE comment.id IN (
 		SELECT il_too.id FROM (
 			SELECT com.id
 				FROM comment AS com
@@ -384,7 +383,7 @@ func FixCommentTypeLabelWithOutsideLabels() (int64, error) {
 
 // CountIssueLabelWithOutsideLabels count label comments with outside label
 func CountIssueLabelWithOutsideLabels() (int64, error) {
-	return x.Where(builder.Expr("(label.org_id = 0 AND issue.repo_id != label.repo_id) OR (label.repo_id = 0 AND label.org_id != repository.owner_id)")).
+	return db.DefaultContext().Engine().Where(builder.Expr("(label.org_id = 0 AND issue.repo_id != label.repo_id) OR (label.repo_id = 0 AND label.org_id != repository.owner_id)")).
 		Table("issue_label").
 		Join("inner", "label", "issue_label.label_id = label.id ").
 		Join("inner", "issue", "issue.id = issue_label.issue_id ").
@@ -394,7 +393,7 @@ func CountIssueLabelWithOutsideLabels() (int64, error) {
 
 // FixIssueLabelWithOutsideLabels fix label comments with outside label
 func FixIssueLabelWithOutsideLabels() (int64, error) {
-	res, err := x.Exec(`DELETE FROM issue_label WHERE issue_label.id IN (
+	res, err := db.DefaultContext().Engine().Exec(`DELETE FROM issue_label WHERE issue_label.id IN (
 		SELECT il_too.id FROM (
 			SELECT il_too_too.id
 				FROM issue_label AS il_too_too
@@ -411,61 +410,3 @@ func FixIssueLabelWithOutsideLabels() (int64, error) {
 
 	return res.RowsAffected()
 }
-
-// CountBadSequences looks for broken sequences from recreate-table mistakes
-func CountBadSequences() (int64, error) {
-	if !setting.Database.UsePostgreSQL {
-		return 0, nil
-	}
-
-	sess := x.NewSession()
-	defer sess.Close()
-
-	var sequences []string
-	schema := sess.Engine().Dialect().URI().Schema
-
-	sess.Engine().SetSchema("")
-	if err := sess.Table("information_schema.sequences").Cols("sequence_name").Where("sequence_name LIKE 'tmp_recreate__%_id_seq%' AND sequence_catalog = ?", setting.Database.Name).Find(&sequences); err != nil {
-		return 0, err
-	}
-	sess.Engine().SetSchema(schema)
-
-	return int64(len(sequences)), nil
-}
-
-// FixBadSequences fixes for broken sequences from recreate-table mistakes
-func FixBadSequences() error {
-	if !setting.Database.UsePostgreSQL {
-		return nil
-	}
-
-	sess := x.NewSession()
-	defer sess.Close()
-	if err := sess.Begin(); err != nil {
-		return err
-	}
-
-	var sequences []string
-	schema := sess.Engine().Dialect().URI().Schema
-
-	sess.Engine().SetSchema("")
-	if err := sess.Table("information_schema.sequences").Cols("sequence_name").Where("sequence_name LIKE 'tmp_recreate__%_id_seq%' AND sequence_catalog = ?", setting.Database.Name).Find(&sequences); err != nil {
-		return err
-	}
-	sess.Engine().SetSchema(schema)
-
-	sequenceRegexp := regexp.MustCompile(`tmp_recreate__(\w+)_id_seq.*`)
-
-	for _, sequence := range sequences {
-		tableName := sequenceRegexp.FindStringSubmatch(sequence)[1]
-		newSequenceName := tableName + "_id_seq"
-		if _, err := sess.Exec(fmt.Sprintf("ALTER SEQUENCE `%s` RENAME TO `%s`", sequence, newSequenceName)); err != nil {
-			return err
-		}
-		if _, err := sess.Exec(fmt.Sprintf("SELECT setval('%s', COALESCE((SELECT MAX(id)+1 FROM `%s`), 1), false)", newSequenceName, tableName)); err != nil {
-			return err
-		}
-	}
-
-	return sess.Commit()
-}
diff --git a/models/consistency_test.go b/models/consistency_test.go
index 0a91d9f3d..25acb467b 100644
--- a/models/consistency_test.go
+++ b/models/consistency_test.go
@@ -7,16 +7,17 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestDeleteOrphanedObjects(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	countBefore, err := x.Count(&PullRequest{})
+	countBefore, err := db.DefaultContext().Engine().Count(&PullRequest{})
 	assert.NoError(t, err)
 
-	_, err = x.Insert(&PullRequest{IssueID: 1000}, &PullRequest{IssueID: 1001}, &PullRequest{IssueID: 1003})
+	_, err = db.DefaultContext().Engine().Insert(&PullRequest{IssueID: 1000}, &PullRequest{IssueID: 1001}, &PullRequest{IssueID: 1003})
 	assert.NoError(t, err)
 
 	orphaned, err := CountOrphanedObjects("pull_request", "issue", "pull_request.issue_id=issue.id")
@@ -26,7 +27,7 @@ func TestDeleteOrphanedObjects(t *testing.T) {
 	err = DeleteOrphanedObjects("pull_request", "issue", "pull_request.issue_id=issue.id")
 	assert.NoError(t, err)
 
-	countAfter, err := x.Count(&PullRequest{})
+	countAfter, err := db.DefaultContext().Engine().Count(&PullRequest{})
 	assert.NoError(t, err)
 	assert.EqualValues(t, countBefore, countAfter)
 }
diff --git a/models/context.go b/models/context.go
deleted file mode 100644
index 8c29f74d2..000000000
--- a/models/context.go
+++ /dev/null
@@ -1,71 +0,0 @@
-// Copyright 2019 The Gitea Authors. All rights reserved.
-// Use of this source code is governed by a MIT-style
-// license that can be found in the LICENSE file.
-
-package models
-
-import (
-	"code.gitea.io/gitea/modules/setting"
-
-	"xorm.io/builder"
-)
-
-// DBContext represents a db context
-type DBContext struct {
-	e Engine
-}
-
-// DefaultDBContext represents a DBContext with default Engine
-func DefaultDBContext() DBContext {
-	return DBContext{x}
-}
-
-// Committer represents an interface to Commit or Close the dbcontext
-type Committer interface {
-	Commit() error
-	Close() error
-}
-
-// TxDBContext represents a transaction DBContext
-func TxDBContext() (DBContext, Committer, error) {
-	sess := x.NewSession()
-	if err := sess.Begin(); err != nil {
-		sess.Close()
-		return DBContext{}, nil, err
-	}
-
-	return DBContext{sess}, sess, nil
-}
-
-// WithContext represents executing database operations
-func WithContext(f func(ctx DBContext) error) error {
-	return f(DBContext{x})
-}
-
-// WithTx represents executing database operations on a transaction
-func WithTx(f func(ctx DBContext) error) error {
-	sess := x.NewSession()
-	defer sess.Close()
-	if err := sess.Begin(); err != nil {
-		return err
-	}
-
-	if err := f(DBContext{sess}); err != nil {
-		return err
-	}
-
-	return sess.Commit()
-}
-
-// Iterate iterates the databases and doing something
-func Iterate(ctx DBContext, tableBean interface{}, cond builder.Cond, fun func(idx int, bean interface{}) error) error {
-	return ctx.e.Where(cond).
-		BufferSize(setting.Database.IterateBufferSize).
-		Iterate(tableBean, fun)
-}
-
-// Insert inserts records into database
-func Insert(ctx DBContext, beans ...interface{}) error {
-	_, err := ctx.e.Insert(beans...)
-	return err
-}
diff --git a/models/db/context.go b/models/db/context.go
new file mode 100644
index 000000000..9b1a3010b
--- /dev/null
+++ b/models/db/context.go
@@ -0,0 +1,86 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package db
+
+import (
+	"code.gitea.io/gitea/modules/setting"
+
+	"xorm.io/builder"
+	"xorm.io/xorm"
+)
+
+// Context represents a db context
+type Context struct {
+	e Engine
+}
+
+// Engine returns db engine
+func (ctx *Context) Engine() Engine {
+	return ctx.e
+}
+
+// NewSession returns a new session
+func (ctx *Context) NewSession() *xorm.Session {
+	e, ok := ctx.e.(*xorm.Engine)
+	if ok {
+		return e.NewSession()
+	}
+	return nil
+}
+
+// DefaultContext represents a Context with default Engine
+func DefaultContext() *Context {
+	return &Context{x}
+}
+
+// Committer represents an interface to Commit or Close the Context
+type Committer interface {
+	Commit() error
+	Close() error
+}
+
+// TxContext represents a transaction Context
+func TxContext() (*Context, Committer, error) {
+	sess := x.NewSession()
+	if err := sess.Begin(); err != nil {
+		sess.Close()
+		return nil, nil, err
+	}
+
+	return &Context{sess}, sess, nil
+}
+
+// WithContext represents executing database operations
+func WithContext(f func(ctx *Context) error) error {
+	return f(&Context{x})
+}
+
+// WithTx represents executing database operations on a transaction
+func WithTx(f func(ctx *Context) error) error {
+	sess := x.NewSession()
+	defer sess.Close()
+	if err := sess.Begin(); err != nil {
+		return err
+	}
+
+	if err := f(&Context{sess}); err != nil {
+		return err
+	}
+
+	return sess.Commit()
+}
+
+// Iterate iterates the databases and doing something
+func Iterate(ctx *Context, tableBean interface{}, cond builder.Cond, fun func(idx int, bean interface{}) error) error {
+	return ctx.e.Where(cond).
+		BufferSize(setting.Database.IterateBufferSize).
+		Iterate(tableBean, fun)
+}
+
+// Insert inserts records into database
+func Insert(ctx *Context, beans ...interface{}) error {
+	_, err := ctx.e.Insert(beans...)
+	return err
+}
diff --git a/models/convert.go b/models/db/convert.go
similarity index 98%
rename from models/convert.go
rename to models/db/convert.go
index 1deb7c66f..bf9a74a9a 100644
--- a/models/convert.go
+++ b/models/db/convert.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a MIT-style
 // license that can be found in the LICENSE file.
 
-package models
+package db
 
 import (
 	"fmt"
diff --git a/models/models.go b/models/db/engine.go
similarity index 66%
rename from models/models.go
rename to models/db/engine.go
index 4e1448241..e71b6fdc5 100755
--- a/models/models.go
+++ b/models/db/engine.go
@@ -3,13 +3,14 @@
 // Use of this source code is governed by a MIT-style
 // license that can be found in the LICENSE file.
 
-package models
+package db
 
 import (
 	"context"
 	"database/sql"
 	"errors"
 	"fmt"
+	"io"
 	"reflect"
 	"strings"
 
@@ -17,7 +18,6 @@ import (
 
 	// Needed for the MySQL driver
 	_ "github.com/go-sql-driver/mysql"
-	lru "github.com/hashicorp/golang-lru"
 	"xorm.io/xorm"
 	"xorm.io/xorm/names"
 	"xorm.io/xorm/schemas"
@@ -29,6 +29,15 @@ import (
 	_ "github.com/denisenkom/go-mssqldb"
 )
 
+var (
+	x         *xorm.Engine
+	tables    []interface{}
+	initFuncs []func() error
+
+	// HasEngine specifies if we have a xorm.Engine
+	HasEngine bool
+)
+
 // Engine represents a xorm engine or session.
 type Engine interface {
 	Table(tableNameOrBean interface{}) *xorm.Session
@@ -51,96 +60,35 @@ type Engine interface {
 	Desc(colNames ...string) *xorm.Session
 	Limit(limit int, start ...int) *xorm.Session
 	SumInt(bean interface{}, columnName string) (res int64, err error)
+	Sync2(...interface{}) error
+	Select(string) *xorm.Session
+	NotIn(string, ...interface{}) *xorm.Session
+	OrderBy(string) *xorm.Session
+	Exist(...interface{}) (bool, error)
+	Distinct(...string) *xorm.Session
+	Query(...interface{}) ([]map[string][]byte, error)
+	Cols(...string) *xorm.Session
 }
 
-const (
-	// When queries are broken down in parts because of the number
-	// of parameters, attempt to break by this amount
-	maxQueryParameters = 300
-)
+// TableInfo returns table's information via an object
+func TableInfo(v interface{}) (*schemas.Table, error) {
+	return x.TableInfo(v)
+}
 
-var (
-	x      *xorm.Engine
-	tables []interface{}
+// DumpTables dump tables information
+func DumpTables(tables []*schemas.Table, w io.Writer, tp ...schemas.DBType) error {
+	return x.DumpTables(tables, w, tp...)
+}
 
-	// HasEngine specifies if we have a xorm.Engine
-	HasEngine bool
-)
+// RegisterModel registers model, if initfunc provided, it will be invoked after data model sync
+func RegisterModel(bean interface{}, initFunc ...func() error) {
+	tables = append(tables, bean)
+	if len(initFuncs) > 0 && initFunc[0] != nil {
+		initFuncs = append(initFuncs, initFunc[0])
+	}
+}
 
 func init() {
-	tables = append(tables,
-		new(User),
-		new(PublicKey),
-		new(AccessToken),
-		new(Repository),
-		new(DeployKey),
-		new(Collaboration),
-		new(Access),
-		new(Upload),
-		new(Watch),
-		new(Star),
-		new(Follow),
-		new(Action),
-		new(Issue),
-		new(PullRequest),
-		new(Comment),
-		new(Attachment),
-		new(Label),
-		new(IssueLabel),
-		new(Milestone),
-		new(Mirror),
-		new(Release),
-		new(LoginSource),
-		new(Webhook),
-		new(HookTask),
-		new(Team),
-		new(OrgUser),
-		new(TeamUser),
-		new(TeamRepo),
-		new(Notice),
-		new(EmailAddress),
-		new(Notification),
-		new(IssueUser),
-		new(LFSMetaObject),
-		new(TwoFactor),
-		new(GPGKey),
-		new(GPGKeyImport),
-		new(RepoUnit),
-		new(RepoRedirect),
-		new(ExternalLoginUser),
-		new(ProtectedBranch),
-		new(UserOpenID),
-		new(IssueWatch),
-		new(CommitStatus),
-		new(Stopwatch),
-		new(TrackedTime),
-		new(DeletedBranch),
-		new(RepoIndexerStatus),
-		new(IssueDependency),
-		new(LFSLock),
-		new(Reaction),
-		new(IssueAssignees),
-		new(U2FRegistration),
-		new(TeamUnit),
-		new(Review),
-		new(OAuth2Application),
-		new(OAuth2AuthorizationCode),
-		new(OAuth2Grant),
-		new(Task),
-		new(LanguageStat),
-		new(EmailHash),
-		new(UserRedirect),
-		new(Project),
-		new(ProjectBoard),
-		new(ProjectIssue),
-		new(Session),
-		new(RepoTransfer),
-		new(IssueIndex),
-		new(PushMirror),
-		new(RepoArchiver),
-		new(ProtectedTag),
-	)
-
 	gonicNames := []string{"SSL", "UID"}
 	for _, name := range gonicNames {
 		names.LintGonicMapper[name] = true
@@ -235,13 +183,10 @@ func NewEngine(ctx context.Context, migrateFunc func(*xorm.Engine) error) (err e
 		return fmt.Errorf("sync database struct error: %v", err)
 	}
 
-	if setting.SuccessfulTokensCacheSize > 0 {
-		successfulAccessTokenCache, err = lru.New(setting.SuccessfulTokensCacheSize)
-		if err != nil {
-			return fmt.Errorf("unable to allocate AccessToken cache: %v", err)
+	for _, initFunc := range initFuncs {
+		if err := initFunc(); err != nil {
+			return fmt.Errorf("initFunc failed: %v", err)
 		}
-	} else {
-		successfulAccessTokenCache = nil
 	}
 
 	return nil
@@ -277,62 +222,6 @@ func NamesToBean(names ...string) ([]interface{}, error) {
 	return beans, nil
 }
 
-// Statistic contains the database statistics
-type Statistic struct {
-	Counter struct {
-		User, Org, PublicKey,
-		Repo, Watch, Star, Action, Access,
-		Issue, IssueClosed, IssueOpen,
-		Comment, Oauth, Follow,
-		Mirror, Release, LoginSource, Webhook,
-		Milestone, Label, HookTask,
-		Team, UpdateTask, Attachment int64
-	}
-}
-
-// GetStatistic returns the database statistics
-func GetStatistic() (stats Statistic) {
-	stats.Counter.User = CountUsers()
-	stats.Counter.Org = CountOrganizations()
-	stats.Counter.PublicKey, _ = x.Count(new(PublicKey))
-	stats.Counter.Repo = CountRepositories(true)
-	stats.Counter.Watch, _ = x.Count(new(Watch))
-	stats.Counter.Star, _ = x.Count(new(Star))
-	stats.Counter.Action, _ = x.Count(new(Action))
-	stats.Counter.Access, _ = x.Count(new(Access))
-
-	type IssueCount struct {
-		Count    int64
-		IsClosed bool
-	}
-	issueCounts := []IssueCount{}
-
-	_ = x.Select("COUNT(*) AS count, is_closed").Table("issue").GroupBy("is_closed").Find(&issueCounts)
-	for _, c := range issueCounts {
-		if c.IsClosed {
-			stats.Counter.IssueClosed = c.Count
-		} else {
-			stats.Counter.IssueOpen = c.Count
-		}
-	}
-
-	stats.Counter.Issue = stats.Counter.IssueClosed + stats.Counter.IssueOpen
-
-	stats.Counter.Comment, _ = x.Count(new(Comment))
-	stats.Counter.Oauth = 0
-	stats.Counter.Follow, _ = x.Count(new(Follow))
-	stats.Counter.Mirror, _ = x.Count(new(Mirror))
-	stats.Counter.Release, _ = x.Count(new(Release))
-	stats.Counter.LoginSource = CountLoginSources()
-	stats.Counter.Webhook, _ = x.Count(new(Webhook))
-	stats.Counter.Milestone, _ = x.Count(new(Milestone))
-	stats.Counter.Label, _ = x.Count(new(Label))
-	stats.Counter.HookTask, _ = x.Count(new(HookTask))
-	stats.Counter.Team, _ = x.Count(new(Team))
-	stats.Counter.Attachment, _ = x.Count(new(Attachment))
-	return
-}
-
 // Ping tests if database is alive
 func Ping() error {
 	if x != nil {
diff --git a/models/index.go b/models/db/index.go
similarity index 89%
rename from models/index.go
rename to models/db/index.go
index 121a149ca..873289db5 100644
--- a/models/index.go
+++ b/models/db/index.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a MIT-style
 // license that can be found in the LICENSE file.
 
-package models
+package db
 
 import (
 	"errors"
@@ -18,11 +18,8 @@ type ResourceIndex struct {
 	MaxIndex int64 `xorm:"index"`
 }
 
-// IssueIndex represents the issue index table
-type IssueIndex ResourceIndex
-
-// upsertResourceIndex the function will not return until it acquires the lock or receives an error.
-func upsertResourceIndex(e Engine, tableName string, groupID int64) (err error) {
+// UpsertResourceIndex the function will not return until it acquires the lock or receives an error.
+func UpsertResourceIndex(e Engine, tableName string, groupID int64) (err error) {
 	// An atomic UPSERT operation (INSERT/UPDATE) is the only operation
 	// that ensures that the key is actually locked.
 	switch {
@@ -75,8 +72,8 @@ func GetNextResourceIndex(tableName string, groupID int64) (int64, error) {
 	return 0, ErrGetResourceIndexFailed
 }
 
-// deleteResouceIndex delete resource index
-func deleteResouceIndex(e Engine, tableName string, groupID int64) error {
+// DeleteResouceIndex delete resource index
+func DeleteResouceIndex(e Engine, tableName string, groupID int64) error {
 	_, err := e.Exec(fmt.Sprintf("DELETE FROM %s WHERE group_id=?", tableName), groupID)
 	return err
 }
@@ -94,7 +91,7 @@ func getNextResourceIndex(tableName string, groupID int64) (int64, error) {
 		return 0, err
 	}
 
-	if err := upsertResourceIndex(sess, tableName, groupID); err != nil {
+	if err := UpsertResourceIndex(sess, tableName, groupID); err != nil {
 		return 0, err
 	}
 
diff --git a/models/log.go b/models/db/log.go
similarity index 99%
rename from models/log.go
rename to models/db/log.go
index caeab094b..f9febf440 100644
--- a/models/log.go
+++ b/models/db/log.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a MIT-style
 // license that can be found in the LICENSE file.
 
-package models
+package db
 
 import (
 	"fmt"
diff --git a/models/db/main_test.go b/models/db/main_test.go
new file mode 100644
index 000000000..f34ff6581
--- /dev/null
+++ b/models/db/main_test.go
@@ -0,0 +1,14 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package db
+
+import (
+	"path/filepath"
+	"testing"
+)
+
+func TestMain(m *testing.M) {
+	MainTest(m, filepath.Join("..", ".."))
+}
diff --git a/models/db/sequence.go b/models/db/sequence.go
new file mode 100644
index 000000000..48e4a8f1a
--- /dev/null
+++ b/models/db/sequence.go
@@ -0,0 +1,70 @@
+// Copyright 2018 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package db
+
+import (
+	"fmt"
+	"regexp"
+
+	"code.gitea.io/gitea/modules/setting"
+)
+
+// CountBadSequences looks for broken sequences from recreate-table mistakes
+func CountBadSequences() (int64, error) {
+	if !setting.Database.UsePostgreSQL {
+		return 0, nil
+	}
+
+	sess := x.NewSession()
+	defer sess.Close()
+
+	var sequences []string
+	schema := x.Dialect().URI().Schema
+
+	sess.Engine().SetSchema("")
+	if err := sess.Table("information_schema.sequences").Cols("sequence_name").Where("sequence_name LIKE 'tmp_recreate__%_id_seq%' AND sequence_catalog = ?", setting.Database.Name).Find(&sequences); err != nil {
+		return 0, err
+	}
+	sess.Engine().SetSchema(schema)
+
+	return int64(len(sequences)), nil
+}
+
+// FixBadSequences fixes for broken sequences from recreate-table mistakes
+func FixBadSequences() error {
+	if !setting.Database.UsePostgreSQL {
+		return nil
+	}
+
+	sess := x.NewSession()
+	defer sess.Close()
+	if err := sess.Begin(); err != nil {
+		return err
+	}
+
+	var sequences []string
+	schema := sess.Engine().Dialect().URI().Schema
+
+	sess.Engine().SetSchema("")
+	if err := sess.Table("information_schema.sequences").Cols("sequence_name").Where("sequence_name LIKE 'tmp_recreate__%_id_seq%' AND sequence_catalog = ?", setting.Database.Name).Find(&sequences); err != nil {
+		return err
+	}
+	sess.Engine().SetSchema(schema)
+
+	sequenceRegexp := regexp.MustCompile(`tmp_recreate__(\w+)_id_seq.*`)
+
+	for _, sequence := range sequences {
+		tableName := sequenceRegexp.FindStringSubmatch(sequence)[1]
+		newSequenceName := tableName + "_id_seq"
+		if _, err := sess.Exec(fmt.Sprintf("ALTER SEQUENCE `%s` RENAME TO `%s`", sequence, newSequenceName)); err != nil {
+			return err
+		}
+		if _, err := sess.Exec(fmt.Sprintf("SELECT setval('%s', COALESCE((SELECT MAX(id)+1 FROM `%s`), 1), false)", newSequenceName, tableName)); err != nil {
+			return err
+		}
+	}
+
+	return sess.Commit()
+}
diff --git a/models/sql_postgres_with_schema.go b/models/db/sql_postgres_with_schema.go
similarity index 99%
rename from models/sql_postgres_with_schema.go
rename to models/db/sql_postgres_with_schema.go
index 0c8893ea2..d6b626292 100644
--- a/models/sql_postgres_with_schema.go
+++ b/models/db/sql_postgres_with_schema.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a MIT-style
 // license that can be found in the LICENSE file.
 
-package models
+package db
 
 import (
 	"database/sql"
diff --git a/models/store.go b/models/db/store.go
similarity index 88%
rename from models/store.go
rename to models/db/store.go
index e8eba28fb..d5931e952 100644
--- a/models/store.go
+++ b/models/db/store.go
@@ -2,9 +2,11 @@
 // Use of this source code is governed by a MIT-style
 // license that can be found in the LICENSE file.
 
-package models
+package db
 
-import "github.com/lafriks/xormstore"
+import (
+	"github.com/lafriks/xormstore"
+)
 
 // CreateStore creates a xormstore for the provided table and key
 func CreateStore(table, key string) (*xormstore.Store, error) {
diff --git a/models/test_fixtures.go b/models/db/test_fixtures.go
similarity index 99%
rename from models/test_fixtures.go
rename to models/db/test_fixtures.go
index c1f84c661..172701513 100644
--- a/models/test_fixtures.go
+++ b/models/db/test_fixtures.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a MIT-style
 // license that can be found in the LICENSE file.
 
-package models
+package db
 
 import (
 	"fmt"
diff --git a/models/unit_tests.go b/models/db/unit_tests.go
similarity index 95%
rename from models/unit_tests.go
rename to models/db/unit_tests.go
index f8d681933..8d834fe11 100644
--- a/models/unit_tests.go
+++ b/models/db/unit_tests.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a MIT-style
 // license that can be found in the LICENSE file.
 
-package models
+package db
 
 import (
 	"fmt"
@@ -32,6 +32,11 @@ var (
 	fixturesDir string
 )
 
+// FixturesDir returns the fixture directory
+func FixturesDir() string {
+	return fixturesDir
+}
+
 func fatalTestError(fmtStr string, args ...interface{}) {
 	fmt.Fprintf(os.Stderr, fmtStr, args...)
 	os.Exit(1)
@@ -152,6 +157,11 @@ func whereConditions(sess *xorm.Session, conditions []interface{}) {
 	}
 }
 
+// LoadBeanIfExists loads beans from fixture database if exist
+func LoadBeanIfExists(bean interface{}, conditions ...interface{}) (bool, error) {
+	return loadBeanIfExists(bean, conditions...)
+}
+
 func loadBeanIfExists(bean interface{}, conditions ...interface{}) (bool, error) {
 	sess := x.NewSession()
 	defer sess.Close()
diff --git a/models/engine_test.go b/models/engine_test.go
new file mode 100644
index 000000000..2c9366751
--- /dev/null
+++ b/models/engine_test.go
@@ -0,0 +1,35 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package models
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/modules/setting"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDumpDatabase(t *testing.T) {
+	assert.NoError(t, db.PrepareTestDatabase())
+
+	dir, err := ioutil.TempDir(os.TempDir(), "dump")
+	assert.NoError(t, err)
+
+	type Version struct {
+		ID      int64 `xorm:"pk autoincr"`
+		Version int64
+	}
+	assert.NoError(t, db.DefaultContext().Engine().Sync2(new(Version)))
+
+	for _, dbName := range setting.SupportedDatabases {
+		dbType := setting.GetDBTypeByName(dbName)
+		assert.NoError(t, db.DumpDatabase(filepath.Join(dir, dbType+".sql"), dbType))
+	}
+}
diff --git a/models/external_login_user.go b/models/external_login_user.go
index aa5da8134..5bfdad699 100644
--- a/models/external_login_user.go
+++ b/models/external_login_user.go
@@ -7,6 +7,7 @@ package models
 import (
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/structs"
 
 	"github.com/markbates/goth"
@@ -34,15 +35,19 @@ type ExternalLoginUser struct {
 	ExpiresAt         time.Time
 }
 
+func init() {
+	db.RegisterModel(new(ExternalLoginUser))
+}
+
 // GetExternalLogin checks if a externalID in loginSourceID scope already exists
 func GetExternalLogin(externalLoginUser *ExternalLoginUser) (bool, error) {
-	return x.Get(externalLoginUser)
+	return db.DefaultContext().Engine().Get(externalLoginUser)
 }
 
 // ListAccountLinks returns a map with the ExternalLoginUser and its LoginSource
 func ListAccountLinks(user *User) ([]*ExternalLoginUser, error) {
 	externalAccounts := make([]*ExternalLoginUser, 0, 5)
-	err := x.Where("user_id=?", user.ID).
+	err := db.DefaultContext().Engine().Where("user_id=?", user.ID).
 		Desc("login_source_id").
 		Find(&externalAccounts)
 	if err != nil {
@@ -54,7 +59,7 @@ func ListAccountLinks(user *User) ([]*ExternalLoginUser, error) {
 
 // LinkExternalToUser link the external user to the user
 func LinkExternalToUser(user *User, externalLoginUser *ExternalLoginUser) error {
-	has, err := x.Where("external_id=? AND login_source_id=?", externalLoginUser.ExternalID, externalLoginUser.LoginSourceID).
+	has, err := db.DefaultContext().Engine().Where("external_id=? AND login_source_id=?", externalLoginUser.ExternalID, externalLoginUser.LoginSourceID).
 		NoAutoCondition().
 		Exist(externalLoginUser)
 	if err != nil {
@@ -63,13 +68,13 @@ func LinkExternalToUser(user *User, externalLoginUser *ExternalLoginUser) error
 		return ErrExternalLoginUserAlreadyExist{externalLoginUser.ExternalID, user.ID, externalLoginUser.LoginSourceID}
 	}
 
-	_, err = x.Insert(externalLoginUser)
+	_, err = db.DefaultContext().Engine().Insert(externalLoginUser)
 	return err
 }
 
 // RemoveAccountLink will remove all external login sources for the given user
 func RemoveAccountLink(user *User, loginSourceID int64) (int64, error) {
-	deleted, err := x.Delete(&ExternalLoginUser{UserID: user.ID, LoginSourceID: loginSourceID})
+	deleted, err := db.DefaultContext().Engine().Delete(&ExternalLoginUser{UserID: user.ID, LoginSourceID: loginSourceID})
 	if err != nil {
 		return deleted, err
 	}
@@ -80,7 +85,7 @@ func RemoveAccountLink(user *User, loginSourceID int64) (int64, error) {
 }
 
 // removeAllAccountLinks will remove all external login sources for the given user
-func removeAllAccountLinks(e Engine, user *User) error {
+func removeAllAccountLinks(e db.Engine, user *User) error {
 	_, err := e.Delete(&ExternalLoginUser{UserID: user.ID})
 	return err
 }
@@ -88,7 +93,7 @@ func removeAllAccountLinks(e Engine, user *User) error {
 // GetUserIDByExternalUserID get user id according to provider and userID
 func GetUserIDByExternalUserID(provider, userID string) (int64, error) {
 	var id int64
-	_, err := x.Table("external_login_user").
+	_, err := db.DefaultContext().Engine().Table("external_login_user").
 		Select("user_id").
 		Where("provider=?", provider).
 		And("external_id=?", userID).
@@ -125,7 +130,7 @@ func UpdateExternalUser(user *User, gothUser goth.User) error {
 		ExpiresAt:         gothUser.ExpiresAt,
 	}
 
-	has, err := x.Where("external_id=? AND login_source_id=?", gothUser.UserID, loginSource.ID).
+	has, err := db.DefaultContext().Engine().Where("external_id=? AND login_source_id=?", gothUser.UserID, loginSource.ID).
 		NoAutoCondition().
 		Exist(externalLoginUser)
 	if err != nil {
@@ -134,7 +139,7 @@ func UpdateExternalUser(user *User, gothUser goth.User) error {
 		return ErrExternalLoginUserNotExist{user.ID, loginSource.ID}
 	}
 
-	_, err = x.Where("external_id=? AND login_source_id=?", gothUser.UserID, loginSource.ID).AllCols().Update(externalLoginUser)
+	_, err = db.DefaultContext().Engine().Where("external_id=? AND login_source_id=?", gothUser.UserID, loginSource.ID).AllCols().Update(externalLoginUser)
 	return err
 }
 
@@ -156,7 +161,7 @@ func (opts FindExternalUserOptions) toConds() builder.Cond {
 // FindExternalUsersByProvider represents external users via provider
 func FindExternalUsersByProvider(opts FindExternalUserOptions) ([]ExternalLoginUser, error) {
 	var users []ExternalLoginUser
-	err := x.Where(opts.toConds()).
+	err := db.DefaultContext().Engine().Where(opts.toConds()).
 		Limit(opts.Limit, opts.Start).
 		OrderBy("login_source_id ASC, external_id ASC").
 		Find(&users)
diff --git a/models/fixture_generation.go b/models/fixture_generation.go
index 64cf16036..49cf5ad6a 100644
--- a/models/fixture_generation.go
+++ b/models/fixture_generation.go
@@ -7,13 +7,15 @@ package models
 import (
 	"fmt"
 	"strings"
+
+	"code.gitea.io/gitea/models/db"
 )
 
 // GetYamlFixturesAccess returns a string containing the contents
 // for the access table, as recalculated using repo.RecalculateAccesses()
 func GetYamlFixturesAccess() (string, error) {
 	repos := make([]*Repository, 0, 50)
-	if err := x.Find(&repos); err != nil {
+	if err := db.DefaultContext().Engine().Find(&repos); err != nil {
 		return "", err
 	}
 
@@ -27,7 +29,7 @@ func GetYamlFixturesAccess() (string, error) {
 	var b strings.Builder
 
 	accesses := make([]*Access, 0, 200)
-	if err := x.OrderBy("user_id, repo_id").Find(&accesses); err != nil {
+	if err := db.DefaultContext().Engine().OrderBy("user_id, repo_id").Find(&accesses); err != nil {
 		return "", err
 	}
 
diff --git a/models/fixture_test.go b/models/fixture_test.go
index 450e374f8..387ee8ff5 100644
--- a/models/fixture_test.go
+++ b/models/fixture_test.go
@@ -9,20 +9,21 @@ import (
 	"path/filepath"
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/util"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestFixtureGeneration(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	test := func(gen func() (string, error), name string) {
 		expected, err := gen()
 		if !assert.NoError(t, err) {
 			return
 		}
-		bytes, err := ioutil.ReadFile(filepath.Join(fixturesDir, name+".yml"))
+		bytes, err := ioutil.ReadFile(filepath.Join(db.FixturesDir(), name+".yml"))
 		if !assert.NoError(t, err) {
 			return
 		}
diff --git a/models/gpg_key.go b/models/gpg_key.go
index cd286604a..fabb3d5c9 100644
--- a/models/gpg_key.go
+++ b/models/gpg_key.go
@@ -9,6 +9,7 @@ import (
 	"strings"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/timeutil"
 
@@ -43,6 +44,10 @@ type GPGKey struct {
 	CanCertify        bool
 }
 
+func init() {
+	db.RegisterModel(new(GPGKey))
+}
+
 // BeforeInsert will be invoked by XORM before inserting a record
 func (key *GPGKey) BeforeInsert() {
 	key.AddedUnix = timeutil.TimeStampNow()
@@ -58,10 +63,10 @@ func (key *GPGKey) AfterLoad(session *xorm.Session) {
 
 // ListGPGKeys returns a list of public keys belongs to given user.
 func ListGPGKeys(uid int64, listOptions ListOptions) ([]*GPGKey, error) {
-	return listGPGKeys(x, uid, listOptions)
+	return listGPGKeys(db.DefaultContext().Engine(), uid, listOptions)
 }
 
-func listGPGKeys(e Engine, uid int64, listOptions ListOptions) ([]*GPGKey, error) {
+func listGPGKeys(e db.Engine, uid int64, listOptions ListOptions) ([]*GPGKey, error) {
 	sess := e.Table(&GPGKey{}).Where("owner_id=? AND primary_key_id=''", uid)
 	if listOptions.Page != 0 {
 		sess = setSessionPagination(sess, &listOptions)
@@ -73,13 +78,13 @@ func listGPGKeys(e Engine, uid int64, listOptions ListOptions) ([]*GPGKey, error
 
 // CountUserGPGKeys return number of gpg keys a user own
 func CountUserGPGKeys(userID int64) (int64, error) {
-	return x.Where("owner_id=? AND primary_key_id=''", userID).Count(&GPGKey{})
+	return db.DefaultContext().Engine().Where("owner_id=? AND primary_key_id=''", userID).Count(&GPGKey{})
 }
 
 // GetGPGKeyByID returns public key by given ID.
 func GetGPGKeyByID(keyID int64) (*GPGKey, error) {
 	key := new(GPGKey)
-	has, err := x.ID(keyID).Get(key)
+	has, err := db.DefaultContext().Engine().ID(keyID).Get(key)
 	if err != nil {
 		return nil, err
 	} else if !has {
@@ -91,7 +96,7 @@ func GetGPGKeyByID(keyID int64) (*GPGKey, error) {
 // GetGPGKeysByKeyID returns public key by given ID.
 func GetGPGKeysByKeyID(keyID string) ([]*GPGKey, error) {
 	keys := make([]*GPGKey, 0, 1)
-	return keys, x.Where("key_id=?", keyID).Find(&keys)
+	return keys, db.DefaultContext().Engine().Where("key_id=?", keyID).Find(&keys)
 }
 
 // GPGKeyToEntity retrieve the imported key and the traducted entity
@@ -195,7 +200,7 @@ func parseGPGKey(ownerID int64, e *openpgp.Entity, verified bool) (*GPGKey, erro
 }
 
 // deleteGPGKey does the actual key deletion
-func deleteGPGKey(e *xorm.Session, keyID string) (int64, error) {
+func deleteGPGKey(e db.Engine, keyID string) (int64, error) {
 	if keyID == "" {
 		return 0, fmt.Errorf("empty KeyId forbidden") // Should never happen but just to be sure
 	}
@@ -222,17 +227,17 @@ func DeleteGPGKey(doer *User, id int64) (err error) {
 		return ErrGPGKeyAccessDenied{doer.ID, key.ID}
 	}
 
-	sess := x.NewSession()
-	defer sess.Close()
-	if err = sess.Begin(); err != nil {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
 		return err
 	}
+	defer committer.Close()
 
-	if _, err = deleteGPGKey(sess, key.KeyID); err != nil {
+	if _, err = deleteGPGKey(ctx.Engine(), key.KeyID); err != nil {
 		return err
 	}
 
-	return sess.Commit()
+	return committer.Commit()
 }
 
 func checkKeyEmails(email string, keys ...*GPGKey) (bool, string) {
diff --git a/models/gpg_key_add.go b/models/gpg_key_add.go
index 1e589e7fe..91a30120a 100644
--- a/models/gpg_key_add.go
+++ b/models/gpg_key_add.go
@@ -7,6 +7,7 @@ package models
 import (
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 
 	"github.com/keybase/go-crypto/openpgp"
@@ -28,7 +29,7 @@ import (
 // This file contains functions relating to adding GPG Keys
 
 // addGPGKey add key, import and subkeys to database
-func addGPGKey(e Engine, key *GPGKey, content string) (err error) {
+func addGPGKey(e db.Engine, key *GPGKey, content string) (err error) {
 	// Add GPGKeyImport
 	if _, err = e.Insert(GPGKeyImport{
 		KeyID:   key.KeyID,
@@ -50,7 +51,7 @@ func addGPGKey(e Engine, key *GPGKey, content string) (err error) {
 }
 
 // addGPGSubKey add subkeys to database
-func addGPGSubKey(e Engine, key *GPGKey) (err error) {
+func addGPGSubKey(e db.Engine, key *GPGKey) (err error) {
 	// Save GPG primary key.
 	if _, err = e.Insert(key); err != nil {
 		return err
@@ -71,11 +72,12 @@ func AddGPGKey(ownerID int64, content, token, signature string) ([]*GPGKey, erro
 		return nil, err
 	}
 
-	sess := x.NewSession()
-	defer sess.Close()
-	if err = sess.Begin(); err != nil {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
 		return nil, err
 	}
+	defer committer.Close()
+
 	keys := make([]*GPGKey, 0, len(ekeys))
 
 	verified := false
@@ -101,7 +103,7 @@ func AddGPGKey(ownerID int64, content, token, signature string) ([]*GPGKey, erro
 
 	for _, ekey := range ekeys {
 		// Key ID cannot be duplicated.
-		has, err := sess.Where("key_id=?", ekey.PrimaryKey.KeyIdString()).
+		has, err := ctx.Engine().Where("key_id=?", ekey.PrimaryKey.KeyIdString()).
 			Get(new(GPGKey))
 		if err != nil {
 			return nil, err
@@ -116,10 +118,10 @@ func AddGPGKey(ownerID int64, content, token, signature string) ([]*GPGKey, erro
 			return nil, err
 		}
 
-		if err = addGPGKey(sess, key, content); err != nil {
+		if err = addGPGKey(ctx.Engine(), key, content); err != nil {
 			return nil, err
 		}
 		keys = append(keys, key)
 	}
-	return keys, sess.Commit()
+	return keys, committer.Commit()
 }
diff --git a/models/gpg_key_import.go b/models/gpg_key_import.go
index bd1d530ec..73d46b4cb 100644
--- a/models/gpg_key_import.go
+++ b/models/gpg_key_import.go
@@ -4,6 +4,8 @@
 
 package models
 
+import "code.gitea.io/gitea/models/db"
+
 //    __________________  ________   ____  __.
 //   /  _____/\______   \/  _____/  |    |/ _|____ ___.__.
 //  /   \  ___ |     ___/   \  ___  |      <_/ __ <   |  |
@@ -25,10 +27,14 @@ type GPGKeyImport struct {
 	Content string `xorm:"TEXT NOT NULL"`
 }
 
+func init() {
+	db.RegisterModel(new(GPGKeyImport))
+}
+
 // GetGPGImportByKeyID returns the import public armored key by given KeyID.
 func GetGPGImportByKeyID(keyID string) (*GPGKeyImport, error) {
 	key := new(GPGKeyImport)
-	has, err := x.ID(keyID).Get(key)
+	has, err := db.DefaultContext().Engine().ID(keyID).Get(key)
 	if err != nil {
 		return nil, err
 	} else if !has {
diff --git a/models/gpg_key_test.go b/models/gpg_key_test.go
index be2d8a223..7a3cbfd67 100644
--- a/models/gpg_key_test.go
+++ b/models/gpg_key_test.go
@@ -8,6 +8,7 @@ import (
 	"testing"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/timeutil"
 
 	"github.com/stretchr/testify/assert"
@@ -192,9 +193,9 @@ Unknown GPG key with good email
 }
 
 func TestCheckGPGUserEmail(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	_ = AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	_ = db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 
 	testEmailWithUpperCaseLetters := `-----BEGIN PGP PUBLIC KEY BLOCK-----
 Version: GnuPG v1
diff --git a/models/gpg_key_verify.go b/models/gpg_key_verify.go
index 15774dc05..050bee0bc 100644
--- a/models/gpg_key_verify.go
+++ b/models/gpg_key_verify.go
@@ -8,6 +8,7 @@ import (
 	"strconv"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/log"
 )
@@ -29,15 +30,15 @@ import (
 
 // VerifyGPGKey marks a GPG key as verified
 func VerifyGPGKey(ownerID int64, keyID, token, signature string) (string, error) {
-	sess := x.NewSession()
-	defer sess.Close()
-	if err := sess.Begin(); err != nil {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
 		return "", err
 	}
+	defer committer.Close()
 
 	key := new(GPGKey)
 
-	has, err := sess.Where("owner_id = ? AND key_id = ?", ownerID, keyID).Get(key)
+	has, err := ctx.Engine().Where("owner_id = ? AND key_id = ?", ownerID, keyID).Get(key)
 	if err != nil {
 		return "", err
 	} else if !has {
@@ -91,11 +92,11 @@ func VerifyGPGKey(ownerID int64, keyID, token, signature string) (string, error)
 	}
 
 	key.Verified = true
-	if _, err := sess.ID(key.ID).SetExpr("verified", true).Update(new(GPGKey)); err != nil {
+	if _, err := ctx.Engine().ID(key.ID).SetExpr("verified", true).Update(new(GPGKey)); err != nil {
 		return "", err
 	}
 
-	if err := sess.Commit(); err != nil {
+	if err := committer.Commit(); err != nil {
 		return "", err
 	}
 
diff --git a/models/index_test.go b/models/index_test.go
deleted file mode 100644
index 40e570ad9..000000000
--- a/models/index_test.go
+++ /dev/null
@@ -1,27 +0,0 @@
-// Copyright 2021 The Gitea Authors. All rights reserved.
-// Use of this source code is governed by a MIT-style
-// license that can be found in the LICENSE file.
-
-package models
-
-import (
-	"fmt"
-	"sync"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestResourceIndex(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-
-	var wg sync.WaitGroup
-	for i := 0; i < 100; i++ {
-		wg.Add(1)
-		go func(i int) {
-			testInsertIssue(t, fmt.Sprintf("issue %d", i+1), "my issue", 0)
-			wg.Done()
-		}(i)
-	}
-	wg.Wait()
-}
diff --git a/models/issue.go b/models/issue.go
index 9e63ac4e5..a1f537358 100644
--- a/models/issue.go
+++ b/models/issue.go
@@ -12,6 +12,7 @@ import (
 	"strconv"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/references"
@@ -82,12 +83,18 @@ const (
 	issueTasksDoneRegexpStr = `(^\s*[-*]\s\[[xX]\]\s.)|(\n\s*[-*]\s\[[xX]\]\s.)`
 )
 
+// IssueIndex represents the issue index table
+type IssueIndex db.ResourceIndex
+
 func init() {
 	issueTasksPat = regexp.MustCompile(issueTasksRegexpStr)
 	issueTasksDonePat = regexp.MustCompile(issueTasksDoneRegexpStr)
+
+	db.RegisterModel(new(Issue))
+	db.RegisterModel(new(IssueIndex))
 }
 
-func (issue *Issue) loadTotalTimes(e Engine) (err error) {
+func (issue *Issue) loadTotalTimes(e db.Engine) (err error) {
 	opts := FindTrackedTimesOptions{IssueID: issue.ID}
 	issue.TotalTrackedTime, err = opts.toSession(e).SumInt(&TrackedTime{}, "time")
 	if err != nil {
@@ -106,10 +113,10 @@ func (issue *Issue) IsOverdue() bool {
 
 // LoadRepo loads issue's repository
 func (issue *Issue) LoadRepo() error {
-	return issue.loadRepo(x)
+	return issue.loadRepo(db.DefaultContext().Engine())
 }
 
-func (issue *Issue) loadRepo(e Engine) (err error) {
+func (issue *Issue) loadRepo(e db.Engine) (err error) {
 	if issue.Repo == nil {
 		issue.Repo, err = getRepositoryByID(e, issue.RepoID)
 		if err != nil {
@@ -121,10 +128,10 @@ func (issue *Issue) loadRepo(e Engine) (err error) {
 
 // IsTimetrackerEnabled returns true if the repo enables timetracking
 func (issue *Issue) IsTimetrackerEnabled() bool {
-	return issue.isTimetrackerEnabled(x)
+	return issue.isTimetrackerEnabled(db.DefaultContext().Engine())
 }
 
-func (issue *Issue) isTimetrackerEnabled(e Engine) bool {
+func (issue *Issue) isTimetrackerEnabled(e db.Engine) bool {
 	if err := issue.loadRepo(e); err != nil {
 		log.Error(fmt.Sprintf("loadRepo: %v", err))
 		return false
@@ -138,7 +145,7 @@ func (issue *Issue) GetPullRequest() (pr *PullRequest, err error) {
 		return nil, fmt.Errorf("Issue is not a pull request")
 	}
 
-	pr, err = getPullRequestByIssueID(x, issue.ID)
+	pr, err = getPullRequestByIssueID(db.DefaultContext().Engine(), issue.ID)
 	if err != nil {
 		return nil, err
 	}
@@ -148,10 +155,10 @@ func (issue *Issue) GetPullRequest() (pr *PullRequest, err error) {
 
 // LoadLabels loads labels
 func (issue *Issue) LoadLabels() error {
-	return issue.loadLabels(x)
+	return issue.loadLabels(db.DefaultContext().Engine())
 }
 
-func (issue *Issue) loadLabels(e Engine) (err error) {
+func (issue *Issue) loadLabels(e db.Engine) (err error) {
 	if issue.Labels == nil {
 		issue.Labels, err = getLabelsByIssueID(e, issue.ID)
 		if err != nil {
@@ -163,10 +170,10 @@ func (issue *Issue) loadLabels(e Engine) (err error) {
 
 // LoadPoster loads poster
 func (issue *Issue) LoadPoster() error {
-	return issue.loadPoster(x)
+	return issue.loadPoster(db.DefaultContext().Engine())
 }
 
-func (issue *Issue) loadPoster(e Engine) (err error) {
+func (issue *Issue) loadPoster(e db.Engine) (err error) {
 	if issue.Poster == nil {
 		issue.Poster, err = getUserByID(e, issue.PosterID)
 		if err != nil {
@@ -182,7 +189,7 @@ func (issue *Issue) loadPoster(e Engine) (err error) {
 	return
 }
 
-func (issue *Issue) loadPullRequest(e Engine) (err error) {
+func (issue *Issue) loadPullRequest(e db.Engine) (err error) {
 	if issue.IsPull && issue.PullRequest == nil {
 		issue.PullRequest, err = getPullRequestByIssueID(e, issue.ID)
 		if err != nil {
@@ -198,19 +205,19 @@ func (issue *Issue) loadPullRequest(e Engine) (err error) {
 
 // LoadPullRequest loads pull request info
 func (issue *Issue) LoadPullRequest() error {
-	return issue.loadPullRequest(x)
+	return issue.loadPullRequest(db.DefaultContext().Engine())
 }
 
-func (issue *Issue) loadComments(e Engine) (err error) {
+func (issue *Issue) loadComments(e db.Engine) (err error) {
 	return issue.loadCommentsByType(e, CommentTypeUnknown)
 }
 
 // LoadDiscussComments loads discuss comments
 func (issue *Issue) LoadDiscussComments() error {
-	return issue.loadCommentsByType(x, CommentTypeComment)
+	return issue.loadCommentsByType(db.DefaultContext().Engine(), CommentTypeComment)
 }
 
-func (issue *Issue) loadCommentsByType(e Engine, tp CommentType) (err error) {
+func (issue *Issue) loadCommentsByType(e db.Engine, tp CommentType) (err error) {
 	if issue.Comments != nil {
 		return nil
 	}
@@ -221,7 +228,7 @@ func (issue *Issue) loadCommentsByType(e Engine, tp CommentType) (err error) {
 	return err
 }
 
-func (issue *Issue) loadReactions(e Engine) (err error) {
+func (issue *Issue) loadReactions(e db.Engine) (err error) {
 	if issue.Reactions != nil {
 		return nil
 	}
@@ -255,7 +262,7 @@ func (issue *Issue) loadReactions(e Engine) (err error) {
 	return nil
 }
 
-func (issue *Issue) loadMilestone(e Engine) (err error) {
+func (issue *Issue) loadMilestone(e db.Engine) (err error) {
 	if (issue.Milestone == nil || issue.Milestone.ID != issue.MilestoneID) && issue.MilestoneID > 0 {
 		issue.Milestone, err = getMilestoneByRepoID(e, issue.RepoID, issue.MilestoneID)
 		if err != nil && !IsErrMilestoneNotExist(err) {
@@ -265,7 +272,7 @@ func (issue *Issue) loadMilestone(e Engine) (err error) {
 	return nil
 }
 
-func (issue *Issue) loadAttributes(e Engine) (err error) {
+func (issue *Issue) loadAttributes(e db.Engine) (err error) {
 	if err = issue.loadRepo(e); err != nil {
 		return
 	}
@@ -320,18 +327,18 @@ func (issue *Issue) loadAttributes(e Engine) (err error) {
 
 // LoadAttributes loads the attribute of this issue.
 func (issue *Issue) LoadAttributes() error {
-	return issue.loadAttributes(x)
+	return issue.loadAttributes(db.DefaultContext().Engine())
 }
 
 // LoadMilestone load milestone of this issue.
 func (issue *Issue) LoadMilestone() error {
-	return issue.loadMilestone(x)
+	return issue.loadMilestone(db.DefaultContext().Engine())
 }
 
 // GetIsRead load the `IsRead` field of the issue
 func (issue *Issue) GetIsRead(userID int64) error {
 	issueUser := &IssueUser{IssueID: issue.ID, UID: userID}
-	if has, err := x.Get(issueUser); err != nil {
+	if has, err := db.DefaultContext().Engine().Get(issueUser); err != nil {
 		return err
 	} else if !has {
 		issue.IsRead = false
@@ -398,13 +405,13 @@ func (issue *Issue) IsPoster(uid int64) bool {
 	return issue.OriginalAuthorID == 0 && issue.PosterID == uid
 }
 
-func (issue *Issue) hasLabel(e Engine, labelID int64) bool {
+func (issue *Issue) hasLabel(e db.Engine, labelID int64) bool {
 	return hasIssueLabel(e, issue.ID, labelID)
 }
 
 // HasLabel returns true if issue has been labeled by given ID.
 func (issue *Issue) HasLabel(labelID int64) bool {
-	return issue.hasLabel(x, labelID)
+	return issue.hasLabel(db.DefaultContext().Engine(), labelID)
 }
 
 // ReplyReference returns tokenized address to use for email reply headers
@@ -419,15 +426,15 @@ func (issue *Issue) ReplyReference() string {
 	return fmt.Sprintf("%s/%s/%d@%s", issue.Repo.FullName(), path, issue.Index, setting.Domain)
 }
 
-func (issue *Issue) addLabel(e *xorm.Session, label *Label, doer *User) error {
+func (issue *Issue) addLabel(e db.Engine, label *Label, doer *User) error {
 	return newIssueLabel(e, issue, label, doer)
 }
 
-func (issue *Issue) addLabels(e *xorm.Session, labels []*Label, doer *User) error {
+func (issue *Issue) addLabels(e db.Engine, labels []*Label, doer *User) error {
 	return newIssueLabels(e, issue, labels, doer)
 }
 
-func (issue *Issue) getLabels(e Engine) (err error) {
+func (issue *Issue) getLabels(e db.Engine) (err error) {
 	if len(issue.Labels) > 0 {
 		return nil
 	}
@@ -439,11 +446,11 @@ func (issue *Issue) getLabels(e Engine) (err error) {
 	return nil
 }
 
-func (issue *Issue) removeLabel(e *xorm.Session, doer *User, label *Label) error {
+func (issue *Issue) removeLabel(e db.Engine, doer *User, label *Label) error {
 	return deleteIssueLabel(e, issue, label, doer)
 }
 
-func (issue *Issue) clearLabels(e *xorm.Session, doer *User) (err error) {
+func (issue *Issue) clearLabels(e db.Engine, doer *User) (err error) {
 	if err = issue.getLabels(e); err != nil {
 		return fmt.Errorf("getLabels: %v", err)
 	}
@@ -460,19 +467,19 @@ func (issue *Issue) clearLabels(e *xorm.Session, doer *User) (err error) {
 // ClearLabels removes all issue labels as the given user.
 // Triggers appropriate WebHooks, if any.
 func (issue *Issue) ClearLabels(doer *User) (err error) {
-	sess := x.NewSession()
-	defer sess.Close()
-	if err = sess.Begin(); err != nil {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
 		return err
 	}
+	defer committer.Close()
 
-	if err := issue.loadRepo(sess); err != nil {
+	if err := issue.loadRepo(ctx.Engine()); err != nil {
 		return err
-	} else if err = issue.loadPullRequest(sess); err != nil {
+	} else if err = issue.loadPullRequest(ctx.Engine()); err != nil {
 		return err
 	}
 
-	perm, err := getUserRepoPermission(sess, issue.Repo, doer)
+	perm, err := getUserRepoPermission(ctx.Engine(), issue.Repo, doer)
 	if err != nil {
 		return err
 	}
@@ -480,11 +487,11 @@ func (issue *Issue) ClearLabels(doer *User) (err error) {
 		return ErrRepoLabelNotExist{}
 	}
 
-	if err = issue.clearLabels(sess, doer); err != nil {
+	if err = issue.clearLabels(ctx.Engine(), doer); err != nil {
 		return err
 	}
 
-	if err = sess.Commit(); err != nil {
+	if err = committer.Commit(); err != nil {
 		return fmt.Errorf("Commit: %v", err)
 	}
 
@@ -508,17 +515,17 @@ func (ts labelSorter) Swap(i, j int) {
 // ReplaceLabels removes all current labels and add new labels to the issue.
 // Triggers appropriate WebHooks, if any.
 func (issue *Issue) ReplaceLabels(labels []*Label, doer *User) (err error) {
-	sess := x.NewSession()
-	defer sess.Close()
-	if err = sess.Begin(); err != nil {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
 		return err
 	}
+	defer committer.Close()
 
-	if err = issue.loadRepo(sess); err != nil {
+	if err = issue.loadRepo(ctx.Engine()); err != nil {
 		return err
 	}
 
-	if err = issue.loadLabels(sess); err != nil {
+	if err = issue.loadLabels(ctx.Engine()); err != nil {
 		return err
 	}
 
@@ -554,23 +561,23 @@ func (issue *Issue) ReplaceLabels(labels []*Label, doer *User) (err error) {
 	toRemove = append(toRemove, issue.Labels[removeIndex:]...)
 
 	if len(toAdd) > 0 {
-		if err = issue.addLabels(sess, toAdd, doer); err != nil {
+		if err = issue.addLabels(ctx.Engine(), toAdd, doer); err != nil {
 			return fmt.Errorf("addLabels: %v", err)
 		}
 	}
 
 	for _, l := range toRemove {
-		if err = issue.removeLabel(sess, doer, l); err != nil {
+		if err = issue.removeLabel(ctx.Engine(), doer, l); err != nil {
 			return fmt.Errorf("removeLabel: %v", err)
 		}
 	}
 
 	issue.Labels = nil
-	if err = issue.loadLabels(sess); err != nil {
+	if err = issue.loadLabels(ctx.Engine()); err != nil {
 		return err
 	}
 
-	return sess.Commit()
+	return committer.Commit()
 }
 
 // ReadBy sets issue to be read by given user.
@@ -579,17 +586,17 @@ func (issue *Issue) ReadBy(userID int64) error {
 		return err
 	}
 
-	return setIssueNotificationStatusReadIfUnread(x, userID, issue.ID)
+	return setIssueNotificationStatusReadIfUnread(db.DefaultContext().Engine(), userID, issue.ID)
 }
 
-func updateIssueCols(e Engine, issue *Issue, cols ...string) error {
+func updateIssueCols(e db.Engine, issue *Issue, cols ...string) error {
 	if _, err := e.ID(issue.ID).Cols(cols...).Update(issue); err != nil {
 		return err
 	}
 	return nil
 }
 
-func (issue *Issue) changeStatus(e *xorm.Session, doer *User, isClosed, isMergePull bool) (*Comment, error) {
+func (issue *Issue) changeStatus(e db.Engine, doer *User, isClosed, isMergePull bool) (*Comment, error) {
 	// Reload the issue
 	currentIssue, err := getIssueByID(e, issue.ID)
 	if err != nil {
@@ -612,7 +619,7 @@ func (issue *Issue) changeStatus(e *xorm.Session, doer *User, isClosed, isMergeP
 	return issue.doChangeStatus(e, doer, isMergePull)
 }
 
-func (issue *Issue) doChangeStatus(e *xorm.Session, doer *User, isMergePull bool) (*Comment, error) {
+func (issue *Issue) doChangeStatus(e db.Engine, doer *User, isMergePull bool) (*Comment, error) {
 	// Check for open dependencies
 	if issue.IsClosed && issue.Repo.isDependenciesEnabled(e) {
 		// only check if dependencies are enabled and we're about to close an issue, otherwise reopening an issue would fail when there are unsatisfied dependencies
@@ -675,25 +682,25 @@ func (issue *Issue) doChangeStatus(e *xorm.Session, doer *User, isMergePull bool
 
 // ChangeStatus changes issue status to open or closed.
 func (issue *Issue) ChangeStatus(doer *User, isClosed bool) (*Comment, error) {
-	sess := x.NewSession()
-	defer sess.Close()
-	if err := sess.Begin(); err != nil {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
 		return nil, err
 	}
+	defer committer.Close()
 
-	if err := issue.loadRepo(sess); err != nil {
+	if err := issue.loadRepo(ctx.Engine()); err != nil {
 		return nil, err
 	}
-	if err := issue.loadPoster(sess); err != nil {
+	if err := issue.loadPoster(ctx.Engine()); err != nil {
 		return nil, err
 	}
 
-	comment, err := issue.changeStatus(sess, doer, isClosed, false)
+	comment, err := issue.changeStatus(ctx.Engine(), doer, isClosed, false)
 	if err != nil {
 		return nil, err
 	}
 
-	if err = sess.Commit(); err != nil {
+	if err = committer.Commit(); err != nil {
 		return nil, fmt.Errorf("Commit: %v", err)
 	}
 
@@ -702,18 +709,17 @@ func (issue *Issue) ChangeStatus(doer *User, isClosed bool) (*Comment, error) {
 
 // ChangeTitle changes the title of this issue, as the given user.
 func (issue *Issue) ChangeTitle(doer *User, oldTitle string) (err error) {
-	sess := x.NewSession()
-	defer sess.Close()
-
-	if err = sess.Begin(); err != nil {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
 		return err
 	}
+	defer committer.Close()
 
-	if err = updateIssueCols(sess, issue, "name"); err != nil {
+	if err = updateIssueCols(ctx.Engine(), issue, "name"); err != nil {
 		return fmt.Errorf("updateIssueCols: %v", err)
 	}
 
-	if err = issue.loadRepo(sess); err != nil {
+	if err = issue.loadRepo(ctx.Engine()); err != nil {
 		return fmt.Errorf("loadRepo: %v", err)
 	}
 
@@ -725,43 +731,42 @@ func (issue *Issue) ChangeTitle(doer *User, oldTitle string) (err error) {
 		OldTitle: oldTitle,
 		NewTitle: issue.Title,
 	}
-	if _, err = createComment(sess, opts); err != nil {
+	if _, err = createComment(ctx.Engine(), opts); err != nil {
 		return fmt.Errorf("createComment: %v", err)
 	}
-	if err = issue.addCrossReferences(sess, doer, true); err != nil {
+	if err = issue.addCrossReferences(ctx.Engine(), doer, true); err != nil {
 		return err
 	}
 
-	return sess.Commit()
+	return committer.Commit()
 }
 
 // ChangeRef changes the branch of this issue, as the given user.
 func (issue *Issue) ChangeRef(doer *User, oldRef string) (err error) {
-	sess := x.NewSession()
-	defer sess.Close()
-
-	if err = sess.Begin(); err != nil {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
 		return err
 	}
+	defer committer.Close()
 
-	if err = updateIssueCols(sess, issue, "ref"); err != nil {
+	if err = updateIssueCols(ctx.Engine(), issue, "ref"); err != nil {
 		return fmt.Errorf("updateIssueCols: %v", err)
 	}
 
-	return sess.Commit()
+	return committer.Commit()
 }
 
 // AddDeletePRBranchComment adds delete branch comment for pull request issue
 func AddDeletePRBranchComment(doer *User, repo *Repository, issueID int64, branchName string) error {
-	issue, err := getIssueByID(x, issueID)
+	issue, err := getIssueByID(db.DefaultContext().Engine(), issueID)
 	if err != nil {
 		return err
 	}
-	sess := x.NewSession()
-	defer sess.Close()
-	if err := sess.Begin(); err != nil {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
 		return err
 	}
+	defer committer.Close()
 	opts := &CreateCommentOptions{
 		Type:   CommentTypeDeleteBranch,
 		Doer:   doer,
@@ -769,52 +774,52 @@ func AddDeletePRBranchComment(doer *User, repo *Repository, issueID int64, branc
 		Issue:  issue,
 		OldRef: branchName,
 	}
-	if _, err = createComment(sess, opts); err != nil {
+	if _, err = createComment(ctx.Engine(), opts); err != nil {
 		return err
 	}
 
-	return sess.Commit()
+	return committer.Commit()
 }
 
 // UpdateAttachments update attachments by UUIDs for the issue
 func (issue *Issue) UpdateAttachments(uuids []string) (err error) {
-	sess := x.NewSession()
-	defer sess.Close()
-	if err = sess.Begin(); err != nil {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
 		return err
 	}
-	attachments, err := getAttachmentsByUUIDs(sess, uuids)
+	defer committer.Close()
+	attachments, err := getAttachmentsByUUIDs(ctx.Engine(), uuids)
 	if err != nil {
 		return fmt.Errorf("getAttachmentsByUUIDs [uuids: %v]: %v", uuids, err)
 	}
 	for i := 0; i < len(attachments); i++ {
 		attachments[i].IssueID = issue.ID
-		if err := updateAttachment(sess, attachments[i]); err != nil {
+		if err := updateAttachment(ctx.Engine(), attachments[i]); err != nil {
 			return fmt.Errorf("update attachment [id: %d]: %v", attachments[i].ID, err)
 		}
 	}
-	return sess.Commit()
+	return committer.Commit()
 }
 
 // ChangeContent changes issue content, as the given user.
 func (issue *Issue) ChangeContent(doer *User, content string) (err error) {
 	issue.Content = content
 
-	sess := x.NewSession()
-	defer sess.Close()
-	if err = sess.Begin(); err != nil {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
 		return err
 	}
+	defer committer.Close()
 
-	if err = updateIssueCols(sess, issue, "content"); err != nil {
+	if err = updateIssueCols(ctx.Engine(), issue, "content"); err != nil {
 		return fmt.Errorf("UpdateIssueCols: %v", err)
 	}
 
-	if err = issue.addCrossReferences(sess, doer, true); err != nil {
+	if err = issue.addCrossReferences(ctx.Engine(), doer, true); err != nil {
 		return err
 	}
 
-	return sess.Commit()
+	return committer.Commit()
 }
 
 // GetTasks returns the amount of tasks in the issues content
@@ -849,7 +854,7 @@ func (issue *Issue) GetLastEventLabel() string {
 // GetLastComment return last comment for the current issue.
 func (issue *Issue) GetLastComment() (*Comment, error) {
 	var c Comment
-	exist, err := x.Where("type = ?", CommentTypeComment).
+	exist, err := db.DefaultContext().Engine().Where("type = ?", CommentTypeComment).
 		And("issue_id = ?", issue.ID).Desc("id").Get(&c)
 	if err != nil {
 		return nil, err
@@ -880,7 +885,7 @@ type NewIssueOptions struct {
 	IsPull      bool
 }
 
-func newIssue(e *xorm.Session, doer *User, opts NewIssueOptions) (err error) {
+func newIssue(e db.Engine, doer *User, opts NewIssueOptions) (err error) {
 	opts.Issue.Title = strings.TrimSpace(opts.Issue.Title)
 
 	if opts.Issue.MilestoneID > 0 {
@@ -985,44 +990,44 @@ func newIssue(e *xorm.Session, doer *User, opts NewIssueOptions) (err error) {
 // RecalculateIssueIndexForRepo create issue_index for repo if not exist and
 // update it based on highest index of existing issues assigned to a repo
 func RecalculateIssueIndexForRepo(repoID int64) error {
-	sess := x.NewSession()
-	defer sess.Close()
-	if err := sess.Begin(); err != nil {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
 		return err
 	}
+	defer committer.Close()
 
-	if err := upsertResourceIndex(sess, "issue_index", repoID); err != nil {
+	if err := db.UpsertResourceIndex(ctx.Engine(), "issue_index", repoID); err != nil {
 		return err
 	}
 
 	var max int64
-	if _, err := sess.Select(" MAX(`index`)").Table("issue").Where("repo_id=?", repoID).Get(&max); err != nil {
+	if _, err := ctx.Engine().Select(" MAX(`index`)").Table("issue").Where("repo_id=?", repoID).Get(&max); err != nil {
 		return err
 	}
 
-	if _, err := sess.Exec("UPDATE `issue_index` SET max_index=? WHERE group_id=?", max, repoID); err != nil {
+	if _, err := ctx.Engine().Exec("UPDATE `issue_index` SET max_index=? WHERE group_id=?", max, repoID); err != nil {
 		return err
 	}
 
-	return sess.Commit()
+	return committer.Commit()
 }
 
 // NewIssue creates new issue with labels for repository.
 func NewIssue(repo *Repository, issue *Issue, labelIDs []int64, uuids []string) (err error) {
-	idx, err := GetNextResourceIndex("issue_index", repo.ID)
+	idx, err := db.GetNextResourceIndex("issue_index", repo.ID)
 	if err != nil {
 		return fmt.Errorf("generate issue index failed: %v", err)
 	}
 
 	issue.Index = idx
 
-	sess := x.NewSession()
-	defer sess.Close()
-	if err = sess.Begin(); err != nil {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
 		return err
 	}
+	defer committer.Close()
 
-	if err = newIssue(sess, issue.Poster, NewIssueOptions{
+	if err = newIssue(ctx.Engine(), issue.Poster, NewIssueOptions{
 		Repo:        repo,
 		Issue:       issue,
 		LabelIDs:    labelIDs,
@@ -1034,7 +1039,7 @@ func NewIssue(repo *Repository, issue *Issue, labelIDs []int64, uuids []string)
 		return fmt.Errorf("newIssue: %v", err)
 	}
 
-	if err = sess.Commit(); err != nil {
+	if err = committer.Commit(); err != nil {
 		return fmt.Errorf("Commit: %v", err)
 	}
 
@@ -1050,7 +1055,7 @@ func GetIssueByIndex(repoID, index int64) (*Issue, error) {
 		RepoID: repoID,
 		Index:  index,
 	}
-	has, err := x.Get(issue)
+	has, err := db.DefaultContext().Engine().Get(issue)
 	if err != nil {
 		return nil, err
 	} else if !has {
@@ -1068,7 +1073,7 @@ func GetIssueWithAttrsByIndex(repoID, index int64) (*Issue, error) {
 	return issue, issue.LoadAttributes()
 }
 
-func getIssueByID(e Engine, id int64) (*Issue, error) {
+func getIssueByID(e db.Engine, id int64) (*Issue, error) {
 	issue := new(Issue)
 	has, err := e.ID(id).Get(issue)
 	if err != nil {
@@ -1081,24 +1086,24 @@ func getIssueByID(e Engine, id int64) (*Issue, error) {
 
 // GetIssueWithAttrsByID returns an issue with attributes by given ID.
 func GetIssueWithAttrsByID(id int64) (*Issue, error) {
-	issue, err := getIssueByID(x, id)
+	issue, err := getIssueByID(db.DefaultContext().Engine(), id)
 	if err != nil {
 		return nil, err
 	}
-	return issue, issue.loadAttributes(x)
+	return issue, issue.loadAttributes(db.DefaultContext().Engine())
 }
 
 // GetIssueByID returns an issue by given ID.
 func GetIssueByID(id int64) (*Issue, error) {
-	return getIssueByID(x, id)
+	return getIssueByID(db.DefaultContext().Engine(), id)
 }
 
-func getIssuesByIDs(e Engine, issueIDs []int64) ([]*Issue, error) {
+func getIssuesByIDs(e db.Engine, issueIDs []int64) ([]*Issue, error) {
 	issues := make([]*Issue, 0, 10)
 	return issues, e.In("id", issueIDs).Find(&issues)
 }
 
-func getIssueIDsByRepoID(e Engine, repoID int64) ([]int64, error) {
+func getIssueIDsByRepoID(e db.Engine, repoID int64) ([]int64, error) {
 	ids := make([]int64, 0, 10)
 	err := e.Table("issue").Cols("id").Where("repo_id = ?", repoID).Find(&ids)
 	return ids, err
@@ -1106,12 +1111,12 @@ func getIssueIDsByRepoID(e Engine, repoID int64) ([]int64, error) {
 
 // GetIssueIDsByRepoID returns all issue ids by repo id
 func GetIssueIDsByRepoID(repoID int64) ([]int64, error) {
-	return getIssueIDsByRepoID(x, repoID)
+	return getIssueIDsByRepoID(db.DefaultContext().Engine(), repoID)
 }
 
 // GetIssuesByIDs return issues with the given IDs.
 func GetIssuesByIDs(issueIDs []int64) ([]*Issue, error) {
-	return getIssuesByIDs(x, issueIDs)
+	return getIssuesByIDs(db.DefaultContext().Engine(), issueIDs)
 }
 
 // IssuesOptions represents options of an issue.
@@ -1311,7 +1316,7 @@ func applyReviewRequestedCondition(sess *xorm.Session, reviewRequestedID int64)
 
 // CountIssuesByRepo map from repoID to number of issues matching the options
 func CountIssuesByRepo(opts *IssuesOptions) (map[int64]int64, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	sess.Join("INNER", "repository", "`issue`.repo_id = `repository`.id")
@@ -1339,7 +1344,7 @@ func CountIssuesByRepo(opts *IssuesOptions) (map[int64]int64, error) {
 // GetRepoIDsForIssuesOptions find all repo ids for the given options
 func GetRepoIDsForIssuesOptions(opts *IssuesOptions, user *User) ([]int64, error) {
 	repoIDs := make([]int64, 0, 5)
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	sess.Join("INNER", "repository", "`issue`.repo_id = `repository`.id")
@@ -1359,7 +1364,7 @@ func GetRepoIDsForIssuesOptions(opts *IssuesOptions, user *User) ([]int64, error
 
 // Issues returns a list of issues by given conditions.
 func Issues(opts *IssuesOptions) ([]*Issue, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	sess.Join("INNER", "repository", "`issue`.repo_id = `repository`.id")
@@ -1381,7 +1386,7 @@ func Issues(opts *IssuesOptions) ([]*Issue, error) {
 
 // CountIssues number return of issues by given conditions.
 func CountIssues(opts *IssuesOptions) (int64, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	countsSlice := make([]*struct {
@@ -1406,7 +1411,7 @@ func CountIssues(opts *IssuesOptions) (int64, error) {
 // User permissions must be verified elsewhere if required.
 func GetParticipantsIDsByIssueID(issueID int64) ([]int64, error) {
 	userIDs := make([]int64, 0, 5)
-	return userIDs, x.Table("comment").
+	return userIDs, db.DefaultContext().Engine().Table("comment").
 		Cols("poster_id").
 		Where("issue_id = ?", issueID).
 		And("type in (?,?,?)", CommentTypeComment, CommentTypeCode, CommentTypeReview).
@@ -1416,7 +1421,7 @@ func GetParticipantsIDsByIssueID(issueID int64) ([]int64, error) {
 
 // IsUserParticipantsOfIssue return true if user is participants of an issue
 func IsUserParticipantsOfIssue(user *User, issue *Issue) bool {
-	userIDs, err := issue.getParticipantIDsByIssue(x)
+	userIDs, err := issue.getParticipantIDsByIssue(db.DefaultContext().Engine())
 	if err != nil {
 		log.Error(err.Error())
 		return false
@@ -1425,7 +1430,7 @@ func IsUserParticipantsOfIssue(user *User, issue *Issue) bool {
 }
 
 // UpdateIssueMentions updates issue-user relations for mentioned users.
-func UpdateIssueMentions(ctx DBContext, issueID int64, mentions []*User) error {
+func UpdateIssueMentions(ctx *db.Context, issueID int64, mentions []*User) error {
 	if len(mentions) == 0 {
 		return nil
 	}
@@ -1482,6 +1487,12 @@ type IssueStatsOptions struct {
 	IssueIDs          []int64
 }
 
+const (
+	// When queries are broken down in parts because of the number
+	// of parameters, attempt to break by this amount
+	maxQueryParameters = 300
+)
+
 // GetIssueStats returns issue statistic information by given conditions.
 func GetIssueStats(opts *IssueStatsOptions) (*IssueStats, error) {
 	if len(opts.IssueIDs) <= maxQueryParameters {
@@ -1518,7 +1529,7 @@ func getIssueStatsChunk(opts *IssueStatsOptions, issueIDs []int64) (*IssueStats,
 	stats := &IssueStats{}
 
 	countSession := func(opts *IssueStatsOptions) *xorm.Session {
-		sess := x.
+		sess := db.DefaultContext().Engine().
 			Where("issue.repo_id = ?", opts.RepoID)
 
 		if len(opts.IssueIDs) > 0 {
@@ -1612,7 +1623,7 @@ func GetUserIssueStats(opts UserIssueStatsOptions) (*IssueStats, error) {
 	}
 
 	sess := func(cond builder.Cond) *xorm.Session {
-		s := x.Where(cond)
+		s := db.DefaultContext().Engine().Where(cond)
 		if len(opts.LabelIDs) > 0 {
 			s.Join("INNER", "issue_label", "issue_label.issue_id = issue.id").
 				In("issue_label.label_id", opts.LabelIDs)
@@ -1724,7 +1735,7 @@ func GetUserIssueStats(opts UserIssueStatsOptions) (*IssueStats, error) {
 // GetRepoIssueStats returns number of open and closed repository issues by given filter mode.
 func GetRepoIssueStats(repoID, uid int64, filterMode int, isPull bool) (numOpen, numClosed int64) {
 	countSession := func(isClosed, isPull bool, repoID int64) *xorm.Session {
-		sess := x.
+		sess := db.DefaultContext().Engine().
 			Where("is_closed = ?", isClosed).
 			And("is_pull = ?", isPull).
 			And("repo_id = ?", repoID)
@@ -1776,7 +1787,7 @@ func SearchIssueIDsByKeyword(kw string, repoIDs []int64, limit, start int) (int6
 		ID          int64
 		UpdatedUnix int64
 	}, 0, limit)
-	err := x.Distinct("id", "updated_unix").Table("issue").Where(cond).
+	err := db.DefaultContext().Engine().Distinct("id", "updated_unix").Table("issue").Where(cond).
 		OrderBy("`updated_unix` DESC").Limit(limit, start).
 		Find(&res)
 	if err != nil {
@@ -1786,7 +1797,7 @@ func SearchIssueIDsByKeyword(kw string, repoIDs []int64, limit, start int) (int6
 		ids = append(ids, r.ID)
 	}
 
-	total, err := x.Distinct("id").Table("issue").Where(cond).Count()
+	total, err := db.DefaultContext().Engine().Distinct("id").Table("issue").Where(cond).Count()
 	if err != nil {
 		return 0, nil, err
 	}
@@ -1798,7 +1809,7 @@ func SearchIssueIDsByKeyword(kw string, repoIDs []int64, limit, start int) (int6
 // If the issue status is changed a statusChangeComment is returned
 // similarly if the title is changed the titleChanged bool is set to true
 func UpdateIssueByAPI(issue *Issue, doer *User) (statusChangeComment *Comment, titleChanged bool, err error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return nil, false, err
@@ -1857,7 +1868,7 @@ func UpdateIssueDeadline(issue *Issue, deadlineUnix timeutil.TimeStamp, doer *Us
 		return nil
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -1883,7 +1894,7 @@ type DependencyInfo struct {
 }
 
 // getParticipantIDsByIssue returns all userIDs who are participated in comments of an issue and issue author
-func (issue *Issue) getParticipantIDsByIssue(e Engine) ([]int64, error) {
+func (issue *Issue) getParticipantIDsByIssue(e db.Engine) ([]int64, error) {
 	if issue == nil {
 		return nil, nil
 	}
@@ -1905,7 +1916,7 @@ func (issue *Issue) getParticipantIDsByIssue(e Engine) ([]int64, error) {
 }
 
 // Get Blocked By Dependencies, aka all issues this issue is blocked by.
-func (issue *Issue) getBlockedByDependencies(e Engine) (issueDeps []*DependencyInfo, err error) {
+func (issue *Issue) getBlockedByDependencies(e db.Engine) (issueDeps []*DependencyInfo, err error) {
 	return issueDeps, e.
 		Table("issue").
 		Join("INNER", "repository", "repository.id = issue.repo_id").
@@ -1917,7 +1928,7 @@ func (issue *Issue) getBlockedByDependencies(e Engine) (issueDeps []*DependencyI
 }
 
 // Get Blocking Dependencies, aka all issues this issue blocks.
-func (issue *Issue) getBlockingDependencies(e Engine) (issueDeps []*DependencyInfo, err error) {
+func (issue *Issue) getBlockingDependencies(e db.Engine) (issueDeps []*DependencyInfo, err error) {
 	return issueDeps, e.
 		Table("issue").
 		Join("INNER", "repository", "repository.id = issue.repo_id").
@@ -1930,15 +1941,15 @@ func (issue *Issue) getBlockingDependencies(e Engine) (issueDeps []*DependencyIn
 
 // BlockedByDependencies finds all Dependencies an issue is blocked by
 func (issue *Issue) BlockedByDependencies() ([]*DependencyInfo, error) {
-	return issue.getBlockedByDependencies(x)
+	return issue.getBlockedByDependencies(db.DefaultContext().Engine())
 }
 
 // BlockingDependencies returns all blocking dependencies, aka all other issues a given issue blocks
 func (issue *Issue) BlockingDependencies() ([]*DependencyInfo, error) {
-	return issue.getBlockingDependencies(x)
+	return issue.getBlockingDependencies(db.DefaultContext().Engine())
 }
 
-func (issue *Issue) updateClosedNum(e Engine) (err error) {
+func (issue *Issue) updateClosedNum(e db.Engine) (err error) {
 	if issue.IsPull {
 		_, err = e.Exec("UPDATE `repository` SET num_closed_pulls=(SELECT count(*) FROM issue WHERE repo_id=? AND is_pull=? AND is_closed=?) WHERE id=?",
 			issue.RepoID,
@@ -1958,7 +1969,7 @@ func (issue *Issue) updateClosedNum(e Engine) (err error) {
 }
 
 // FindAndUpdateIssueMentions finds users mentioned in the given content string, and saves them in the database.
-func (issue *Issue) FindAndUpdateIssueMentions(ctx DBContext, doer *User, content string) (mentions []*User, err error) {
+func (issue *Issue) FindAndUpdateIssueMentions(ctx *db.Context, doer *User, content string) (mentions []*User, err error) {
 	rawMentions := references.FindAllMentionsMarkdown(content)
 	mentions, err = issue.ResolveMentionsByVisibility(ctx, doer, rawMentions)
 	if err != nil {
@@ -1972,18 +1983,18 @@ func (issue *Issue) FindAndUpdateIssueMentions(ctx DBContext, doer *User, conten
 
 // ResolveMentionsByVisibility returns the users mentioned in an issue, removing those that
 // don't have access to reading it. Teams are expanded into their users, but organizations are ignored.
-func (issue *Issue) ResolveMentionsByVisibility(ctx DBContext, doer *User, mentions []string) (users []*User, err error) {
+func (issue *Issue) ResolveMentionsByVisibility(ctx *db.Context, doer *User, mentions []string) (users []*User, err error) {
 	if len(mentions) == 0 {
 		return
 	}
-	if err = issue.loadRepo(ctx.e); err != nil {
+	if err = issue.loadRepo(ctx.Engine()); err != nil {
 		return
 	}
 
 	resolved := make(map[string]bool, 10)
 	var mentionTeams []string
 
-	if err := issue.Repo.getOwner(ctx.e); err != nil {
+	if err := issue.Repo.getOwner(ctx.Engine()); err != nil {
 		return nil, err
 	}
 
@@ -2012,7 +2023,7 @@ func (issue *Issue) ResolveMentionsByVisibility(ctx DBContext, doer *User, menti
 
 	if issue.Repo.Owner.IsOrganization() && len(mentionTeams) > 0 {
 		teams := make([]*Team, 0, len(mentionTeams))
-		if err := ctx.e.
+		if err := ctx.Engine().
 			Join("INNER", "team_repo", "team_repo.team_id = team.id").
 			Where("team_repo.repo_id=?", issue.Repo.ID).
 			In("team.lower_name", mentionTeams).
@@ -2031,7 +2042,7 @@ func (issue *Issue) ResolveMentionsByVisibility(ctx DBContext, doer *User, menti
 					resolved[issue.Repo.Owner.LowerName+"/"+team.LowerName] = true
 					continue
 				}
-				has, err := ctx.e.Get(&TeamUnit{OrgID: issue.Repo.Owner.ID, TeamID: team.ID, Type: unittype})
+				has, err := ctx.Engine().Get(&TeamUnit{OrgID: issue.Repo.Owner.ID, TeamID: team.ID, Type: unittype})
 				if err != nil {
 					return nil, fmt.Errorf("get team units (%d): %v", team.ID, err)
 				}
@@ -2042,7 +2053,7 @@ func (issue *Issue) ResolveMentionsByVisibility(ctx DBContext, doer *User, menti
 			}
 			if len(checked) != 0 {
 				teamusers := make([]*User, 0, 20)
-				if err := ctx.e.
+				if err := ctx.Engine().
 					Join("INNER", "team_user", "team_user.uid = `user`.id").
 					In("`team_user`.team_id", checked).
 					And("`user`.is_active = ?", true).
@@ -2079,7 +2090,7 @@ func (issue *Issue) ResolveMentionsByVisibility(ctx DBContext, doer *User, menti
 	}
 
 	unchecked := make([]*User, 0, len(mentionUsers))
-	if err := ctx.e.
+	if err := ctx.Engine().
 		Where("`user`.is_active = ?", true).
 		And("`user`.prohibit_login = ?", false).
 		In("`user`.lower_name", mentionUsers).
@@ -2091,7 +2102,7 @@ func (issue *Issue) ResolveMentionsByVisibility(ctx DBContext, doer *User, menti
 			continue
 		}
 		// Normal users must have read access to the referencing issue
-		perm, err := getUserRepoPermission(ctx.e, issue.Repo, user)
+		perm, err := getUserRepoPermission(ctx.Engine(), issue.Repo, user)
 		if err != nil {
 			return nil, fmt.Errorf("getUserRepoPermission [%d]: %v", user.ID, err)
 		}
@@ -2106,7 +2117,7 @@ func (issue *Issue) ResolveMentionsByVisibility(ctx DBContext, doer *User, menti
 
 // UpdateIssuesMigrationsByType updates all migrated repositories' issues from gitServiceType to replace originalAuthorID to posterID
 func UpdateIssuesMigrationsByType(gitServiceType structs.GitServiceType, originalAuthorID string, posterID int64) error {
-	_, err := x.Table("issue").
+	_, err := db.DefaultContext().Engine().Table("issue").
 		Where("repo_id IN (SELECT id FROM repository WHERE original_service_type = ?)", gitServiceType).
 		And("original_author_id = ?", originalAuthorID).
 		Update(map[string]interface{}{
@@ -2119,7 +2130,7 @@ func UpdateIssuesMigrationsByType(gitServiceType structs.GitServiceType, origina
 
 // UpdateReactionsMigrationsByType updates all migrated repositories' reactions from gitServiceType to replace originalAuthorID to posterID
 func UpdateReactionsMigrationsByType(gitServiceType structs.GitServiceType, originalAuthorID string, userID int64) error {
-	_, err := x.Table("reaction").
+	_, err := db.DefaultContext().Engine().Table("reaction").
 		Where("original_author_id = ?", originalAuthorID).
 		And(migratedIssueCond(gitServiceType)).
 		Update(map[string]interface{}{
@@ -2130,7 +2141,7 @@ func UpdateReactionsMigrationsByType(gitServiceType structs.GitServiceType, orig
 	return err
 }
 
-func deleteIssuesByRepoID(sess Engine, repoID int64) (attachmentPaths []string, err error) {
+func deleteIssuesByRepoID(sess db.Engine, repoID int64) (attachmentPaths []string, err error) {
 	deleteCond := builder.Select("id").From("issue").Where(builder.Eq{"issue.repo_id": repoID})
 
 	// Delete comments and attachments
diff --git a/models/issue_assignees.go b/models/issue_assignees.go
index e05c0f0fd..6b2d8bb34 100644
--- a/models/issue_assignees.go
+++ b/models/issue_assignees.go
@@ -7,6 +7,7 @@ package models
 import (
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/util"
 
 	"xorm.io/xorm"
@@ -19,13 +20,17 @@ type IssueAssignees struct {
 	IssueID    int64 `xorm:"INDEX"`
 }
 
+func init() {
+	db.RegisterModel(new(IssueAssignees))
+}
+
 // LoadAssignees load assignees of this issue.
 func (issue *Issue) LoadAssignees() error {
-	return issue.loadAssignees(x)
+	return issue.loadAssignees(db.DefaultContext().Engine())
 }
 
 // This loads all assignees of an issue
-func (issue *Issue) loadAssignees(e Engine) (err error) {
+func (issue *Issue) loadAssignees(e db.Engine) (err error) {
 	// Reset maybe preexisting assignees
 	issue.Assignees = []*User{}
 
@@ -51,7 +56,7 @@ func (issue *Issue) loadAssignees(e Engine) (err error) {
 // User permissions must be verified elsewhere if required.
 func GetAssigneeIDsByIssue(issueID int64) ([]int64, error) {
 	userIDs := make([]int64, 0, 5)
-	return userIDs, x.Table("issue_assignees").
+	return userIDs, db.DefaultContext().Engine().Table("issue_assignees").
 		Cols("assignee_id").
 		Where("issue_id = ?", issueID).
 		Distinct("assignee_id").
@@ -60,10 +65,10 @@ func GetAssigneeIDsByIssue(issueID int64) ([]int64, error) {
 
 // GetAssigneesByIssue returns everyone assigned to that issue
 func GetAssigneesByIssue(issue *Issue) (assignees []*User, err error) {
-	return getAssigneesByIssue(x, issue)
+	return getAssigneesByIssue(db.DefaultContext().Engine(), issue)
 }
 
-func getAssigneesByIssue(e Engine, issue *Issue) (assignees []*User, err error) {
+func getAssigneesByIssue(e db.Engine, issue *Issue) (assignees []*User, err error) {
 	err = issue.loadAssignees(e)
 	if err != nil {
 		return assignees, err
@@ -74,22 +79,22 @@ func getAssigneesByIssue(e Engine, issue *Issue) (assignees []*User, err error)
 
 // IsUserAssignedToIssue returns true when the user is assigned to the issue
 func IsUserAssignedToIssue(issue *Issue, user *User) (isAssigned bool, err error) {
-	return isUserAssignedToIssue(x, issue, user)
+	return isUserAssignedToIssue(db.DefaultContext().Engine(), issue, user)
 }
 
-func isUserAssignedToIssue(e Engine, issue *Issue, user *User) (isAssigned bool, err error) {
+func isUserAssignedToIssue(e db.Engine, issue *Issue, user *User) (isAssigned bool, err error) {
 	return e.Get(&IssueAssignees{IssueID: issue.ID, AssigneeID: user.ID})
 }
 
 // ClearAssigneeByUserID deletes all assignments of an user
-func clearAssigneeByUserID(sess Engine, userID int64) (err error) {
+func clearAssigneeByUserID(sess db.Engine, userID int64) (err error) {
 	_, err = sess.Delete(&IssueAssignees{AssigneeID: userID})
 	return
 }
 
 // ToggleAssignee changes a user between assigned and not assigned for this issue, and make issue comment for it.
 func (issue *Issue) ToggleAssignee(doer *User, assigneeID int64) (removed bool, comment *Comment, err error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	if err := sess.Begin(); err != nil {
diff --git a/models/issue_assignees_test.go b/models/issue_assignees_test.go
index e0359b0b9..5052df3df 100644
--- a/models/issue_assignees_test.go
+++ b/models/issue_assignees_test.go
@@ -7,11 +7,12 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestUpdateAssignee(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// Fake issue with assignees
 	issue, err := GetIssueWithAttrsByID(1)
@@ -61,10 +62,10 @@ func TestUpdateAssignee(t *testing.T) {
 }
 
 func TestMakeIDsFromAPIAssigneesToAdd(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	_ = AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
-	_ = AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	_ = db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	_ = db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 
 	IDs, err := MakeIDsFromAPIAssigneesToAdd("", []string{""})
 	assert.NoError(t, err)
diff --git a/models/issue_comment.go b/models/issue_comment.go
index b079ea960..059d5b08a 100644
--- a/models/issue_comment.go
+++ b/models/issue_comment.go
@@ -13,6 +13,7 @@ import (
 	"strings"
 	"unicode/utf8"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/json"
 	"code.gitea.io/gitea/modules/log"
@@ -197,6 +198,10 @@ type Comment struct {
 	IsForcePush bool                      `xorm:"-"`
 }
 
+func init() {
+	db.RegisterModel(new(Comment))
+}
+
 // PushActionContent is content of push pull comment
 type PushActionContent struct {
 	IsForcePush bool     `json:"is_force_push"`
@@ -205,10 +210,10 @@ type PushActionContent struct {
 
 // LoadIssue loads issue from database
 func (c *Comment) LoadIssue() (err error) {
-	return c.loadIssue(x)
+	return c.loadIssue(db.DefaultContext().Engine())
 }
 
-func (c *Comment) loadIssue(e Engine) (err error) {
+func (c *Comment) loadIssue(e db.Engine) (err error) {
 	if c.Issue != nil {
 		return nil
 	}
@@ -243,7 +248,7 @@ func (c *Comment) AfterLoad(session *xorm.Session) {
 	}
 }
 
-func (c *Comment) loadPoster(e Engine) (err error) {
+func (c *Comment) loadPoster(e db.Engine) (err error) {
 	if c.PosterID <= 0 || c.Poster != nil {
 		return nil
 	}
@@ -279,7 +284,7 @@ func (c *Comment) HTMLURL() string {
 		log.Error("LoadIssue(%d): %v", c.IssueID, err)
 		return ""
 	}
-	err = c.Issue.loadRepo(x)
+	err = c.Issue.loadRepo(db.DefaultContext().Engine())
 	if err != nil { // Silently dropping errors :unamused:
 		log.Error("loadRepo(%d): %v", c.Issue.RepoID, err)
 		return ""
@@ -308,7 +313,7 @@ func (c *Comment) APIURL() string {
 		log.Error("LoadIssue(%d): %v", c.IssueID, err)
 		return ""
 	}
-	err = c.Issue.loadRepo(x)
+	err = c.Issue.loadRepo(db.DefaultContext().Engine())
 	if err != nil { // Silently dropping errors :unamused:
 		log.Error("loadRepo(%d): %v", c.Issue.RepoID, err)
 		return ""
@@ -329,7 +334,7 @@ func (c *Comment) IssueURL() string {
 		return ""
 	}
 
-	err = c.Issue.loadRepo(x)
+	err = c.Issue.loadRepo(db.DefaultContext().Engine())
 	if err != nil { // Silently dropping errors :unamused:
 		log.Error("loadRepo(%d): %v", c.Issue.RepoID, err)
 		return ""
@@ -345,7 +350,7 @@ func (c *Comment) PRURL() string {
 		return ""
 	}
 
-	err = c.Issue.loadRepo(x)
+	err = c.Issue.loadRepo(db.DefaultContext().Engine())
 	if err != nil { // Silently dropping errors :unamused:
 		log.Error("loadRepo(%d): %v", c.Issue.RepoID, err)
 		return ""
@@ -375,7 +380,7 @@ func (c *Comment) EventTag() string {
 // LoadLabel if comment.Type is CommentTypeLabel, then load Label
 func (c *Comment) LoadLabel() error {
 	var label Label
-	has, err := x.ID(c.LabelID).Get(&label)
+	has, err := db.DefaultContext().Engine().ID(c.LabelID).Get(&label)
 	if err != nil {
 		return err
 	} else if has {
@@ -392,7 +397,7 @@ func (c *Comment) LoadLabel() error {
 func (c *Comment) LoadProject() error {
 	if c.OldProjectID > 0 {
 		var oldProject Project
-		has, err := x.ID(c.OldProjectID).Get(&oldProject)
+		has, err := db.DefaultContext().Engine().ID(c.OldProjectID).Get(&oldProject)
 		if err != nil {
 			return err
 		} else if has {
@@ -402,7 +407,7 @@ func (c *Comment) LoadProject() error {
 
 	if c.ProjectID > 0 {
 		var project Project
-		has, err := x.ID(c.ProjectID).Get(&project)
+		has, err := db.DefaultContext().Engine().ID(c.ProjectID).Get(&project)
 		if err != nil {
 			return err
 		} else if has {
@@ -417,7 +422,7 @@ func (c *Comment) LoadProject() error {
 func (c *Comment) LoadMilestone() error {
 	if c.OldMilestoneID > 0 {
 		var oldMilestone Milestone
-		has, err := x.ID(c.OldMilestoneID).Get(&oldMilestone)
+		has, err := db.DefaultContext().Engine().ID(c.OldMilestoneID).Get(&oldMilestone)
 		if err != nil {
 			return err
 		} else if has {
@@ -427,7 +432,7 @@ func (c *Comment) LoadMilestone() error {
 
 	if c.MilestoneID > 0 {
 		var milestone Milestone
-		has, err := x.ID(c.MilestoneID).Get(&milestone)
+		has, err := db.DefaultContext().Engine().ID(c.MilestoneID).Get(&milestone)
 		if err != nil {
 			return err
 		} else if has {
@@ -439,7 +444,7 @@ func (c *Comment) LoadMilestone() error {
 
 // LoadPoster loads comment poster
 func (c *Comment) LoadPoster() error {
-	return c.loadPoster(x)
+	return c.loadPoster(db.DefaultContext().Engine())
 }
 
 // LoadAttachments loads attachments
@@ -449,7 +454,7 @@ func (c *Comment) LoadAttachments() error {
 	}
 
 	var err error
-	c.Attachments, err = getAttachmentsByCommentID(x, c.ID)
+	c.Attachments, err = getAttachmentsByCommentID(db.DefaultContext().Engine(), c.ID)
 	if err != nil {
 		log.Error("getAttachmentsByCommentID[%d]: %v", c.ID, err)
 	}
@@ -458,7 +463,7 @@ func (c *Comment) LoadAttachments() error {
 
 // UpdateAttachments update attachments by UUIDs for the comment
 func (c *Comment) UpdateAttachments(uuids []string) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -482,7 +487,7 @@ func (c *Comment) LoadAssigneeUserAndTeam() error {
 	var err error
 
 	if c.AssigneeID > 0 && c.Assignee == nil {
-		c.Assignee, err = getUserByID(x, c.AssigneeID)
+		c.Assignee, err = getUserByID(db.DefaultContext().Engine(), c.AssigneeID)
 		if err != nil {
 			if !IsErrUserNotExist(err) {
 				return err
@@ -517,7 +522,7 @@ func (c *Comment) LoadResolveDoer() (err error) {
 	if c.ResolveDoerID == 0 || c.Type != CommentTypeCode {
 		return nil
 	}
-	c.ResolveDoer, err = getUserByID(x, c.ResolveDoerID)
+	c.ResolveDoer, err = getUserByID(db.DefaultContext().Engine(), c.ResolveDoerID)
 	if err != nil {
 		if IsErrUserNotExist(err) {
 			c.ResolveDoer = NewGhostUser()
@@ -537,7 +542,7 @@ func (c *Comment) LoadDepIssueDetails() (err error) {
 	if c.DependentIssueID <= 0 || c.DependentIssue != nil {
 		return nil
 	}
-	c.DependentIssue, err = getIssueByID(x, c.DependentIssueID)
+	c.DependentIssue, err = getIssueByID(db.DefaultContext().Engine(), c.DependentIssueID)
 	return err
 }
 
@@ -551,7 +556,7 @@ func (c *Comment) LoadTime() error {
 	return err
 }
 
-func (c *Comment) loadReactions(e Engine, repo *Repository) (err error) {
+func (c *Comment) loadReactions(e db.Engine, repo *Repository) (err error) {
 	if c.Reactions != nil {
 		return nil
 	}
@@ -571,10 +576,10 @@ func (c *Comment) loadReactions(e Engine, repo *Repository) (err error) {
 
 // LoadReactions loads comment reactions
 func (c *Comment) LoadReactions(repo *Repository) error {
-	return c.loadReactions(x, repo)
+	return c.loadReactions(db.DefaultContext().Engine(), repo)
 }
 
-func (c *Comment) loadReview(e Engine) (err error) {
+func (c *Comment) loadReview(e db.Engine) (err error) {
 	if c.Review == nil {
 		if c.Review, err = getReviewByID(e, c.ReviewID); err != nil {
 			return err
@@ -586,7 +591,7 @@ func (c *Comment) loadReview(e Engine) (err error) {
 
 // LoadReview loads the associated review
 func (c *Comment) LoadReview() error {
-	return c.loadReview(x)
+	return c.loadReview(db.DefaultContext().Engine())
 }
 
 var notEnoughLines = regexp.MustCompile(`fatal: file .* has only \d+ lines?`)
@@ -637,7 +642,7 @@ func (c *Comment) CodeCommentURL() string {
 		log.Error("LoadIssue(%d): %v", c.IssueID, err)
 		return ""
 	}
-	err = c.Issue.loadRepo(x)
+	err = c.Issue.loadRepo(db.DefaultContext().Engine())
 	if err != nil { // Silently dropping errors :unamused:
 		log.Error("loadRepo(%d): %v", c.Issue.RepoID, err)
 		return ""
@@ -681,7 +686,7 @@ func (c *Comment) LoadPushCommits() (err error) {
 	return err
 }
 
-func createComment(e *xorm.Session, opts *CreateCommentOptions) (_ *Comment, err error) {
+func createComment(e db.Engine, opts *CreateCommentOptions) (_ *Comment, err error) {
 	var LabelID int64
 	if opts.Label != nil {
 		LabelID = opts.Label.ID
@@ -740,7 +745,7 @@ func createComment(e *xorm.Session, opts *CreateCommentOptions) (_ *Comment, err
 	return comment, nil
 }
 
-func updateCommentInfos(e *xorm.Session, opts *CreateCommentOptions, comment *Comment) (err error) {
+func updateCommentInfos(e db.Engine, opts *CreateCommentOptions, comment *Comment) (err error) {
 	// Check comment type.
 	switch opts.Type {
 	case CommentTypeCode:
@@ -894,7 +899,7 @@ type CreateCommentOptions struct {
 
 // CreateComment creates comment of issue or commit.
 func CreateComment(opts *CreateCommentOptions) (comment *Comment, err error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return nil, err
@@ -919,7 +924,7 @@ func CreateRefComment(doer *User, repo *Repository, issue *Issue, content, commi
 	}
 
 	// Check if same reference from same commit has already existed.
-	has, err := x.Get(&Comment{
+	has, err := db.DefaultContext().Engine().Get(&Comment{
 		Type:      CommentTypeCommitRef,
 		IssueID:   issue.ID,
 		CommitSHA: commitSHA,
@@ -943,10 +948,10 @@ func CreateRefComment(doer *User, repo *Repository, issue *Issue, content, commi
 
 // GetCommentByID returns the comment by given ID.
 func GetCommentByID(id int64) (*Comment, error) {
-	return getCommentByID(x, id)
+	return getCommentByID(db.DefaultContext().Engine(), id)
 }
 
-func getCommentByID(e Engine, id int64) (*Comment, error) {
+func getCommentByID(e db.Engine, id int64) (*Comment, error) {
 	c := new(Comment)
 	has, err := e.ID(id).Get(c)
 	if err != nil {
@@ -999,7 +1004,7 @@ func (opts *FindCommentsOptions) toConds() builder.Cond {
 	return cond
 }
 
-func findComments(e Engine, opts *FindCommentsOptions) ([]*Comment, error) {
+func findComments(e db.Engine, opts *FindCommentsOptions) ([]*Comment, error) {
 	comments := make([]*Comment, 0, 10)
 	sess := e.Where(opts.toConds())
 	if opts.RepoID > 0 {
@@ -1020,12 +1025,12 @@ func findComments(e Engine, opts *FindCommentsOptions) ([]*Comment, error) {
 
 // FindComments returns all comments according options
 func FindComments(opts *FindCommentsOptions) ([]*Comment, error) {
-	return findComments(x, opts)
+	return findComments(db.DefaultContext().Engine(), opts)
 }
 
 // CountComments count all comments according options by ignoring pagination
 func CountComments(opts *FindCommentsOptions) (int64, error) {
-	sess := x.Where(opts.toConds())
+	sess := db.DefaultContext().Engine().Where(opts.toConds())
 	if opts.RepoID > 0 {
 		sess.Join("INNER", "issue", "issue.id = comment.issue_id")
 	}
@@ -1034,7 +1039,7 @@ func CountComments(opts *FindCommentsOptions) (int64, error) {
 
 // UpdateComment updates information of comment.
 func UpdateComment(c *Comment, doer *User) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -1058,7 +1063,7 @@ func UpdateComment(c *Comment, doer *User) error {
 
 // DeleteComment deletes the comment
 func DeleteComment(comment *Comment) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -1071,7 +1076,7 @@ func DeleteComment(comment *Comment) error {
 	return sess.Commit()
 }
 
-func deleteComment(e Engine, comment *Comment) error {
+func deleteComment(e db.Engine, comment *Comment) error {
 	if _, err := e.Delete(&Comment{
 		ID: comment.ID,
 	}); err != nil {
@@ -1097,11 +1102,11 @@ func deleteComment(e Engine, comment *Comment) error {
 // CodeComments represents comments on code by using this structure: FILENAME -> LINE (+ == proposed; - == previous) -> COMMENTS
 type CodeComments map[string]map[int64][]*Comment
 
-func fetchCodeComments(e Engine, issue *Issue, currentUser *User) (CodeComments, error) {
+func fetchCodeComments(e db.Engine, issue *Issue, currentUser *User) (CodeComments, error) {
 	return fetchCodeCommentsByReview(e, issue, currentUser, nil)
 }
 
-func fetchCodeCommentsByReview(e Engine, issue *Issue, currentUser *User, review *Review) (CodeComments, error) {
+func fetchCodeCommentsByReview(e db.Engine, issue *Issue, currentUser *User, review *Review) (CodeComments, error) {
 	pathToLineToComment := make(CodeComments)
 	if review == nil {
 		review = &Review{ID: 0}
@@ -1126,7 +1131,7 @@ func fetchCodeCommentsByReview(e Engine, issue *Issue, currentUser *User, review
 	return pathToLineToComment, nil
 }
 
-func findCodeComments(e Engine, opts FindCommentsOptions, issue *Issue, currentUser *User, review *Review) ([]*Comment, error) {
+func findCodeComments(e db.Engine, opts FindCommentsOptions, issue *Issue, currentUser *User, review *Review) ([]*Comment, error) {
 	var comments []*Comment
 	if review == nil {
 		review = &Review{ID: 0}
@@ -1202,17 +1207,17 @@ func FetchCodeCommentsByLine(issue *Issue, currentUser *User, treePath string, l
 		TreePath: treePath,
 		Line:     line,
 	}
-	return findCodeComments(x, opts, issue, currentUser, nil)
+	return findCodeComments(db.DefaultContext().Engine(), opts, issue, currentUser, nil)
 }
 
 // FetchCodeComments will return a 2d-map: ["Path"]["Line"] = Comments at line
 func FetchCodeComments(issue *Issue, currentUser *User) (CodeComments, error) {
-	return fetchCodeComments(x, issue, currentUser)
+	return fetchCodeComments(db.DefaultContext().Engine(), issue, currentUser)
 }
 
 // UpdateCommentsMigrationsByType updates comments' migrations information via given git service type and original id and poster id
 func UpdateCommentsMigrationsByType(tp structs.GitServiceType, originalAuthorID string, posterID int64) error {
-	_, err := x.Table("comment").
+	_, err := db.DefaultContext().Engine().Table("comment").
 		Where(builder.In("issue_id",
 			builder.Select("issue.id").
 				From("issue").
diff --git a/models/issue_comment_list.go b/models/issue_comment_list.go
index df1b1ac55..b80fa129e 100644
--- a/models/issue_comment_list.go
+++ b/models/issue_comment_list.go
@@ -4,6 +4,8 @@
 
 package models
 
+import "code.gitea.io/gitea/models/db"
+
 // CommentList defines a list of comments
 type CommentList []*Comment
 
@@ -17,7 +19,7 @@ func (comments CommentList) getPosterIDs() []int64 {
 	return keysInt64(posterIDs)
 }
 
-func (comments CommentList) loadPosters(e Engine) error {
+func (comments CommentList) loadPosters(e db.Engine) error {
 	if len(comments) == 0 {
 		return nil
 	}
@@ -70,7 +72,7 @@ func (comments CommentList) getLabelIDs() []int64 {
 	return keysInt64(ids)
 }
 
-func (comments CommentList) loadLabels(e Engine) error {
+func (comments CommentList) loadLabels(e db.Engine) error {
 	if len(comments) == 0 {
 		return nil
 	}
@@ -120,7 +122,7 @@ func (comments CommentList) getMilestoneIDs() []int64 {
 	return keysInt64(ids)
 }
 
-func (comments CommentList) loadMilestones(e Engine) error {
+func (comments CommentList) loadMilestones(e db.Engine) error {
 	if len(comments) == 0 {
 		return nil
 	}
@@ -163,7 +165,7 @@ func (comments CommentList) getOldMilestoneIDs() []int64 {
 	return keysInt64(ids)
 }
 
-func (comments CommentList) loadOldMilestones(e Engine) error {
+func (comments CommentList) loadOldMilestones(e db.Engine) error {
 	if len(comments) == 0 {
 		return nil
 	}
@@ -206,7 +208,7 @@ func (comments CommentList) getAssigneeIDs() []int64 {
 	return keysInt64(ids)
 }
 
-func (comments CommentList) loadAssignees(e Engine) error {
+func (comments CommentList) loadAssignees(e db.Engine) error {
 	if len(comments) == 0 {
 		return nil
 	}
@@ -280,7 +282,7 @@ func (comments CommentList) Issues() IssueList {
 	return issueList
 }
 
-func (comments CommentList) loadIssues(e Engine) error {
+func (comments CommentList) loadIssues(e db.Engine) error {
 	if len(comments) == 0 {
 		return nil
 	}
@@ -337,7 +339,7 @@ func (comments CommentList) getDependentIssueIDs() []int64 {
 	return keysInt64(ids)
 }
 
-func (comments CommentList) loadDependentIssues(e Engine) error {
+func (comments CommentList) loadDependentIssues(e db.Engine) error {
 	if len(comments) == 0 {
 		return nil
 	}
@@ -386,7 +388,7 @@ func (comments CommentList) loadDependentIssues(e Engine) error {
 	return nil
 }
 
-func (comments CommentList) loadAttachments(e Engine) (err error) {
+func (comments CommentList) loadAttachments(e db.Engine) (err error) {
 	if len(comments) == 0 {
 		return nil
 	}
@@ -438,7 +440,7 @@ func (comments CommentList) getReviewIDs() []int64 {
 	return keysInt64(ids)
 }
 
-func (comments CommentList) loadReviews(e Engine) error {
+func (comments CommentList) loadReviews(e db.Engine) error {
 	if len(comments) == 0 {
 		return nil
 	}
@@ -481,7 +483,7 @@ func (comments CommentList) loadReviews(e Engine) error {
 }
 
 // loadAttributes loads all attributes
-func (comments CommentList) loadAttributes(e Engine) (err error) {
+func (comments CommentList) loadAttributes(e db.Engine) (err error) {
 	if err = comments.loadPosters(e); err != nil {
 		return
 	}
@@ -524,20 +526,20 @@ func (comments CommentList) loadAttributes(e Engine) (err error) {
 // LoadAttributes loads attributes of the comments, except for attachments and
 // comments
 func (comments CommentList) LoadAttributes() error {
-	return comments.loadAttributes(x)
+	return comments.loadAttributes(db.DefaultContext().Engine())
 }
 
 // LoadAttachments loads attachments
 func (comments CommentList) LoadAttachments() error {
-	return comments.loadAttachments(x)
+	return comments.loadAttachments(db.DefaultContext().Engine())
 }
 
 // LoadPosters loads posters
 func (comments CommentList) LoadPosters() error {
-	return comments.loadPosters(x)
+	return comments.loadPosters(db.DefaultContext().Engine())
 }
 
 // LoadIssues loads issues of comments
 func (comments CommentList) LoadIssues() error {
-	return comments.loadIssues(x)
+	return comments.loadIssues(db.DefaultContext().Engine())
 }
diff --git a/models/issue_comment_test.go b/models/issue_comment_test.go
index 91dd5c173..78199881c 100644
--- a/models/issue_comment_test.go
+++ b/models/issue_comment_test.go
@@ -8,15 +8,16 @@ import (
 	"testing"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestCreateComment(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	issue := AssertExistsAndLoadBean(t, &Issue{}).(*Issue)
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: issue.RepoID}).(*Repository)
-	doer := AssertExistsAndLoadBean(t, &User{ID: repo.OwnerID}).(*User)
+	issue := db.AssertExistsAndLoadBean(t, &Issue{}).(*Issue)
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: issue.RepoID}).(*Repository)
+	doer := db.AssertExistsAndLoadBean(t, &User{ID: repo.OwnerID}).(*User)
 
 	now := time.Now().Unix()
 	comment, err := CreateComment(&CreateCommentOptions{
@@ -33,18 +34,18 @@ func TestCreateComment(t *testing.T) {
 	assert.EqualValues(t, "Hello", comment.Content)
 	assert.EqualValues(t, issue.ID, comment.IssueID)
 	assert.EqualValues(t, doer.ID, comment.PosterID)
-	AssertInt64InRange(t, now, then, int64(comment.CreatedUnix))
-	AssertExistsAndLoadBean(t, comment) // assert actually added to DB
+	db.AssertInt64InRange(t, now, then, int64(comment.CreatedUnix))
+	db.AssertExistsAndLoadBean(t, comment) // assert actually added to DB
 
-	updatedIssue := AssertExistsAndLoadBean(t, &Issue{ID: issue.ID}).(*Issue)
-	AssertInt64InRange(t, now, then, int64(updatedIssue.UpdatedUnix))
+	updatedIssue := db.AssertExistsAndLoadBean(t, &Issue{ID: issue.ID}).(*Issue)
+	db.AssertInt64InRange(t, now, then, int64(updatedIssue.UpdatedUnix))
 }
 
 func TestFetchCodeComments(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	issue := AssertExistsAndLoadBean(t, &Issue{ID: 2}).(*Issue)
-	user := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	issue := db.AssertExistsAndLoadBean(t, &Issue{ID: 2}).(*Issue)
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 	res, err := FetchCodeComments(issue, user)
 	assert.NoError(t, err)
 	assert.Contains(t, res, "README.md")
@@ -52,7 +53,7 @@ func TestFetchCodeComments(t *testing.T) {
 	assert.Len(t, res["README.md"][4], 1)
 	assert.Equal(t, int64(4), res["README.md"][4][0].ID)
 
-	user2 := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user2 := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	res, err = FetchCodeComments(issue, user2)
 	assert.NoError(t, err)
 	assert.Len(t, res, 1)
diff --git a/models/issue_dependency.go b/models/issue_dependency.go
index 4008008f3..42ec5715f 100644
--- a/models/issue_dependency.go
+++ b/models/issue_dependency.go
@@ -5,6 +5,7 @@
 package models
 
 import (
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/timeutil"
@@ -20,6 +21,10 @@ type IssueDependency struct {
 	UpdatedUnix  timeutil.TimeStamp `xorm:"updated"`
 }
 
+func init() {
+	db.RegisterModel(new(IssueDependency))
+}
+
 // DependencyType Defines Dependency Type Constants
 type DependencyType int
 
@@ -31,7 +36,7 @@ const (
 
 // CreateIssueDependency creates a new dependency for an issue
 func CreateIssueDependency(user *User, issue, dep *Issue) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -72,7 +77,7 @@ func CreateIssueDependency(user *User, issue, dep *Issue) error {
 
 // RemoveIssueDependency removes a dependency from an issue
 func RemoveIssueDependency(user *User, issue, dep *Issue, depType DependencyType) (err error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -107,16 +112,16 @@ func RemoveIssueDependency(user *User, issue, dep *Issue, depType DependencyType
 }
 
 // Check if the dependency already exists
-func issueDepExists(e Engine, issueID, depID int64) (bool, error) {
+func issueDepExists(e db.Engine, issueID, depID int64) (bool, error) {
 	return e.Where("(issue_id = ? AND dependency_id = ?)", issueID, depID).Exist(&IssueDependency{})
 }
 
 // IssueNoDependenciesLeft checks if issue can be closed
 func IssueNoDependenciesLeft(issue *Issue) (bool, error) {
-	return issueNoDependenciesLeft(x, issue)
+	return issueNoDependenciesLeft(db.DefaultContext().Engine(), issue)
 }
 
-func issueNoDependenciesLeft(e Engine, issue *Issue) (bool, error) {
+func issueNoDependenciesLeft(e db.Engine, issue *Issue) (bool, error) {
 	exists, err := e.
 		Table("issue_dependency").
 		Select("issue.*").
@@ -130,10 +135,10 @@ func issueNoDependenciesLeft(e Engine, issue *Issue) (bool, error) {
 
 // IsDependenciesEnabled returns if dependencies are enabled and returns the default setting if not set.
 func (repo *Repository) IsDependenciesEnabled() bool {
-	return repo.isDependenciesEnabled(x)
+	return repo.isDependenciesEnabled(db.DefaultContext().Engine())
 }
 
-func (repo *Repository) isDependenciesEnabled(e Engine) bool {
+func (repo *Repository) isDependenciesEnabled(e db.Engine) bool {
 	var u *RepoUnit
 	var err error
 	if u, err = repo.getUnit(e, UnitTypeIssues); err != nil {
diff --git a/models/issue_dependency_test.go b/models/issue_dependency_test.go
index bf323abb9..10872645b 100644
--- a/models/issue_dependency_test.go
+++ b/models/issue_dependency_test.go
@@ -7,12 +7,13 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestCreateIssueDependency(t *testing.T) {
 	// Prepare
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	user1, err := GetUserByID(1)
 	assert.NoError(t, err)
@@ -37,7 +38,7 @@ func TestCreateIssueDependency(t *testing.T) {
 	assert.Error(t, err)
 	assert.True(t, IsErrCircularDependency(err))
 
-	_ = AssertExistsAndLoadBean(t, &Comment{Type: CommentTypeAddDependency, PosterID: user1.ID, IssueID: issue1.ID})
+	_ = db.AssertExistsAndLoadBean(t, &Comment{Type: CommentTypeAddDependency, PosterID: user1.ID, IssueID: issue1.ID})
 
 	// Check if dependencies left is correct
 	left, err := IssueNoDependenciesLeft(issue1)
diff --git a/models/issue_label.go b/models/issue_label.go
index 7d7d67020..5d7555e2b 100644
--- a/models/issue_label.go
+++ b/models/issue_label.go
@@ -13,10 +13,10 @@ import (
 	"strconv"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/timeutil"
 
 	"xorm.io/builder"
-	"xorm.io/xorm"
 )
 
 // LabelColorPattern is a regexp witch can validate LabelColor
@@ -43,6 +43,11 @@ type Label struct {
 	IsExcluded        bool   `xorm:"-"`
 }
 
+func init() {
+	db.RegisterModel(new(Label))
+	db.RegisterModel(new(IssueLabel))
+}
+
 // GetLabelTemplateFile loads the label template file by given name,
 // then parses and returns a list of name-color pairs and optionally description.
 func GetLabelTemplateFile(name string) ([][3]string, error) {
@@ -209,7 +214,7 @@ func LoadLabelsFormatted(labelTemplate string) (string, error) {
 	return strings.Join(labels, ", "), err
 }
 
-func initializeLabels(e Engine, id int64, labelTemplate string, isOrg bool) error {
+func initializeLabels(e db.Engine, id int64, labelTemplate string, isOrg bool) error {
 	list, err := GetLabelTemplateFile(labelTemplate)
 	if err != nil {
 		return err
@@ -237,11 +242,11 @@ func initializeLabels(e Engine, id int64, labelTemplate string, isOrg bool) erro
 }
 
 // InitializeLabels adds a label set to a repository using a template
-func InitializeLabels(ctx DBContext, repoID int64, labelTemplate string, isOrg bool) error {
-	return initializeLabels(ctx.e, repoID, labelTemplate, isOrg)
+func InitializeLabels(ctx *db.Context, repoID int64, labelTemplate string, isOrg bool) error {
+	return initializeLabels(ctx.Engine(), repoID, labelTemplate, isOrg)
 }
 
-func newLabel(e Engine, label *Label) error {
+func newLabel(e db.Engine, label *Label) error {
 	_, err := e.Insert(label)
 	return err
 }
@@ -251,25 +256,26 @@ func NewLabel(label *Label) error {
 	if !LabelColorPattern.MatchString(label.Color) {
 		return fmt.Errorf("bad color code: %s", label.Color)
 	}
-	return newLabel(x, label)
+	return newLabel(db.DefaultContext().Engine(), label)
 }
 
 // NewLabels creates new labels
 func NewLabels(labels ...*Label) error {
-	sess := x.NewSession()
-	defer sess.Close()
-	if err := sess.Begin(); err != nil {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
 		return err
 	}
+	defer committer.Close()
+
 	for _, label := range labels {
 		if !LabelColorPattern.MatchString(label.Color) {
 			return fmt.Errorf("bad color code: %s", label.Color)
 		}
-		if err := newLabel(sess, label); err != nil {
+		if err := newLabel(ctx.Engine(), label); err != nil {
 			return err
 		}
 	}
-	return sess.Commit()
+	return committer.Commit()
 }
 
 // UpdateLabel updates label information.
@@ -277,7 +283,7 @@ func UpdateLabel(l *Label) error {
 	if !LabelColorPattern.MatchString(l.Color) {
 		return fmt.Errorf("bad color code: %s", l.Color)
 	}
-	return updateLabelCols(x, l, "name", "description", "color")
+	return updateLabelCols(db.DefaultContext().Engine(), l, "name", "description", "color")
 }
 
 // DeleteLabel delete a label
@@ -290,7 +296,7 @@ func DeleteLabel(id, labelID int64) error {
 		return err
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -320,7 +326,7 @@ func DeleteLabel(id, labelID int64) error {
 }
 
 // getLabelByID returns a label by label id
-func getLabelByID(e Engine, labelID int64) (*Label, error) {
+func getLabelByID(e db.Engine, labelID int64) (*Label, error) {
 	if labelID <= 0 {
 		return nil, ErrLabelNotExist{labelID}
 	}
@@ -337,13 +343,13 @@ func getLabelByID(e Engine, labelID int64) (*Label, error) {
 
 // GetLabelByID returns a label by given ID.
 func GetLabelByID(id int64) (*Label, error) {
-	return getLabelByID(x, id)
+	return getLabelByID(db.DefaultContext().Engine(), id)
 }
 
 // GetLabelsByIDs returns a list of labels by IDs
 func GetLabelsByIDs(labelIDs []int64) ([]*Label, error) {
 	labels := make([]*Label, 0, len(labelIDs))
-	return labels, x.Table("label").
+	return labels, db.DefaultContext().Engine().Table("label").
 		In("id", labelIDs).
 		Asc("name").
 		Cols("id", "repo_id", "org_id").
@@ -358,7 +364,7 @@ func GetLabelsByIDs(labelIDs []int64) ([]*Label, error) {
 //         \/     \/|__|              \/                       \/
 
 // getLabelInRepoByName returns a label by Name in given repository.
-func getLabelInRepoByName(e Engine, repoID int64, labelName string) (*Label, error) {
+func getLabelInRepoByName(e db.Engine, repoID int64, labelName string) (*Label, error) {
 	if len(labelName) == 0 || repoID <= 0 {
 		return nil, ErrRepoLabelNotExist{0, repoID}
 	}
@@ -377,7 +383,7 @@ func getLabelInRepoByName(e Engine, repoID int64, labelName string) (*Label, err
 }
 
 // getLabelInRepoByID returns a label by ID in given repository.
-func getLabelInRepoByID(e Engine, repoID, labelID int64) (*Label, error) {
+func getLabelInRepoByID(e db.Engine, repoID, labelID int64) (*Label, error) {
 	if labelID <= 0 || repoID <= 0 {
 		return nil, ErrRepoLabelNotExist{labelID, repoID}
 	}
@@ -397,7 +403,7 @@ func getLabelInRepoByID(e Engine, repoID, labelID int64) (*Label, error) {
 
 // GetLabelInRepoByName returns a label by name in given repository.
 func GetLabelInRepoByName(repoID int64, labelName string) (*Label, error) {
-	return getLabelInRepoByName(x, repoID, labelName)
+	return getLabelInRepoByName(db.DefaultContext().Engine(), repoID, labelName)
 }
 
 // GetLabelIDsInRepoByNames returns a list of labelIDs by names in a given
@@ -405,7 +411,7 @@ func GetLabelInRepoByName(repoID int64, labelName string) (*Label, error) {
 // it silently ignores label names that do not belong to the repository.
 func GetLabelIDsInRepoByNames(repoID int64, labelNames []string) ([]int64, error) {
 	labelIDs := make([]int64, 0, len(labelNames))
-	return labelIDs, x.Table("label").
+	return labelIDs, db.DefaultContext().Engine().Table("label").
 		Where("repo_id = ?", repoID).
 		In("name", labelNames).
 		Asc("name").
@@ -426,21 +432,21 @@ func BuildLabelNamesIssueIDsCondition(labelNames []string) *builder.Builder {
 
 // GetLabelInRepoByID returns a label by ID in given repository.
 func GetLabelInRepoByID(repoID, labelID int64) (*Label, error) {
-	return getLabelInRepoByID(x, repoID, labelID)
+	return getLabelInRepoByID(db.DefaultContext().Engine(), repoID, labelID)
 }
 
 // GetLabelsInRepoByIDs returns a list of labels by IDs in given repository,
 // it silently ignores label IDs that do not belong to the repository.
 func GetLabelsInRepoByIDs(repoID int64, labelIDs []int64) ([]*Label, error) {
 	labels := make([]*Label, 0, len(labelIDs))
-	return labels, x.
+	return labels, db.DefaultContext().Engine().
 		Where("repo_id = ?", repoID).
 		In("id", labelIDs).
 		Asc("name").
 		Find(&labels)
 }
 
-func getLabelsByRepoID(e Engine, repoID int64, sortType string, listOptions ListOptions) ([]*Label, error) {
+func getLabelsByRepoID(e db.Engine, repoID int64, sortType string, listOptions ListOptions) ([]*Label, error) {
 	if repoID <= 0 {
 		return nil, ErrRepoLabelNotExist{0, repoID}
 	}
@@ -467,12 +473,12 @@ func getLabelsByRepoID(e Engine, repoID int64, sortType string, listOptions List
 
 // GetLabelsByRepoID returns all labels that belong to given repository by ID.
 func GetLabelsByRepoID(repoID int64, sortType string, listOptions ListOptions) ([]*Label, error) {
-	return getLabelsByRepoID(x, repoID, sortType, listOptions)
+	return getLabelsByRepoID(db.DefaultContext().Engine(), repoID, sortType, listOptions)
 }
 
 // CountLabelsByRepoID count number of all labels that belong to given repository by ID.
 func CountLabelsByRepoID(repoID int64) (int64, error) {
-	return x.Where("repo_id = ?", repoID).Count(&Label{})
+	return db.DefaultContext().Engine().Where("repo_id = ?", repoID).Count(&Label{})
 }
 
 // ________
@@ -483,7 +489,7 @@ func CountLabelsByRepoID(repoID int64) (int64, error) {
 //         \/     /_____/
 
 // getLabelInOrgByName returns a label by Name in given organization
-func getLabelInOrgByName(e Engine, orgID int64, labelName string) (*Label, error) {
+func getLabelInOrgByName(e db.Engine, orgID int64, labelName string) (*Label, error) {
 	if len(labelName) == 0 || orgID <= 0 {
 		return nil, ErrOrgLabelNotExist{0, orgID}
 	}
@@ -502,7 +508,7 @@ func getLabelInOrgByName(e Engine, orgID int64, labelName string) (*Label, error
 }
 
 // getLabelInOrgByID returns a label by ID in given organization.
-func getLabelInOrgByID(e Engine, orgID, labelID int64) (*Label, error) {
+func getLabelInOrgByID(e db.Engine, orgID, labelID int64) (*Label, error) {
 	if labelID <= 0 || orgID <= 0 {
 		return nil, ErrOrgLabelNotExist{labelID, orgID}
 	}
@@ -522,7 +528,7 @@ func getLabelInOrgByID(e Engine, orgID, labelID int64) (*Label, error) {
 
 // GetLabelInOrgByName returns a label by name in given organization.
 func GetLabelInOrgByName(orgID int64, labelName string) (*Label, error) {
-	return getLabelInOrgByName(x, orgID, labelName)
+	return getLabelInOrgByName(db.DefaultContext().Engine(), orgID, labelName)
 }
 
 // GetLabelIDsInOrgByNames returns a list of labelIDs by names in a given
@@ -533,7 +539,7 @@ func GetLabelIDsInOrgByNames(orgID int64, labelNames []string) ([]int64, error)
 	}
 	labelIDs := make([]int64, 0, len(labelNames))
 
-	return labelIDs, x.Table("label").
+	return labelIDs, db.DefaultContext().Engine().Table("label").
 		Where("org_id = ?", orgID).
 		In("name", labelNames).
 		Asc("name").
@@ -543,21 +549,21 @@ func GetLabelIDsInOrgByNames(orgID int64, labelNames []string) ([]int64, error)
 
 // GetLabelInOrgByID returns a label by ID in given organization.
 func GetLabelInOrgByID(orgID, labelID int64) (*Label, error) {
-	return getLabelInOrgByID(x, orgID, labelID)
+	return getLabelInOrgByID(db.DefaultContext().Engine(), orgID, labelID)
 }
 
 // GetLabelsInOrgByIDs returns a list of labels by IDs in given organization,
 // it silently ignores label IDs that do not belong to the organization.
 func GetLabelsInOrgByIDs(orgID int64, labelIDs []int64) ([]*Label, error) {
 	labels := make([]*Label, 0, len(labelIDs))
-	return labels, x.
+	return labels, db.DefaultContext().Engine().
 		Where("org_id = ?", orgID).
 		In("id", labelIDs).
 		Asc("name").
 		Find(&labels)
 }
 
-func getLabelsByOrgID(e Engine, orgID int64, sortType string, listOptions ListOptions) ([]*Label, error) {
+func getLabelsByOrgID(e db.Engine, orgID int64, sortType string, listOptions ListOptions) ([]*Label, error) {
 	if orgID <= 0 {
 		return nil, ErrOrgLabelNotExist{0, orgID}
 	}
@@ -584,12 +590,12 @@ func getLabelsByOrgID(e Engine, orgID int64, sortType string, listOptions ListOp
 
 // GetLabelsByOrgID returns all labels that belong to given organization by ID.
 func GetLabelsByOrgID(orgID int64, sortType string, listOptions ListOptions) ([]*Label, error) {
-	return getLabelsByOrgID(x, orgID, sortType, listOptions)
+	return getLabelsByOrgID(db.DefaultContext().Engine(), orgID, sortType, listOptions)
 }
 
 // CountLabelsByOrgID count all labels that belong to given organization by ID.
 func CountLabelsByOrgID(orgID int64) (int64, error) {
-	return x.Where("org_id = ?", orgID).Count(&Label{})
+	return db.DefaultContext().Engine().Where("org_id = ?", orgID).Count(&Label{})
 }
 
 // .___
@@ -599,7 +605,7 @@ func CountLabelsByOrgID(orgID int64) (int64, error) {
 // |___/____  >____  >____/  \___ |
 //          \/     \/            \/
 
-func getLabelsByIssueID(e Engine, issueID int64) ([]*Label, error) {
+func getLabelsByIssueID(e db.Engine, issueID int64) ([]*Label, error) {
 	var labels []*Label
 	return labels, e.Where("issue_label.issue_id = ?", issueID).
 		Join("LEFT", "issue_label", "issue_label.label_id = label.id").
@@ -609,10 +615,10 @@ func getLabelsByIssueID(e Engine, issueID int64) ([]*Label, error) {
 
 // GetLabelsByIssueID returns all labels that belong to given issue by ID.
 func GetLabelsByIssueID(issueID int64) ([]*Label, error) {
-	return getLabelsByIssueID(x, issueID)
+	return getLabelsByIssueID(db.DefaultContext().Engine(), issueID)
 }
 
-func updateLabelCols(e Engine, l *Label, cols ...string) error {
+func updateLabelCols(e db.Engine, l *Label, cols ...string) error {
 	_, err := e.ID(l.ID).
 		SetExpr("num_issues",
 			builder.Select("count(*)").From("issue_label").
@@ -644,19 +650,19 @@ type IssueLabel struct {
 	LabelID int64 `xorm:"UNIQUE(s)"`
 }
 
-func hasIssueLabel(e Engine, issueID, labelID int64) bool {
+func hasIssueLabel(e db.Engine, issueID, labelID int64) bool {
 	has, _ := e.Where("issue_id = ? AND label_id = ?", issueID, labelID).Get(new(IssueLabel))
 	return has
 }
 
 // HasIssueLabel returns true if issue has been labeled.
 func HasIssueLabel(issueID, labelID int64) bool {
-	return hasIssueLabel(x, issueID, labelID)
+	return hasIssueLabel(db.DefaultContext().Engine(), issueID, labelID)
 }
 
 // newIssueLabel this function creates a new label it does not check if the label is valid for the issue
 // YOU MUST CHECK THIS BEFORE THIS FUNCTION
-func newIssueLabel(e *xorm.Session, issue *Issue, label *Label, doer *User) (err error) {
+func newIssueLabel(e db.Engine, issue *Issue, label *Label, doer *User) (err error) {
 	if _, err = e.Insert(&IssueLabel{
 		IssueID: issue.ID,
 		LabelID: label.ID,
@@ -689,7 +695,7 @@ func NewIssueLabel(issue *Issue, label *Label, doer *User) (err error) {
 		return nil
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -717,7 +723,7 @@ func NewIssueLabel(issue *Issue, label *Label, doer *User) (err error) {
 }
 
 // newIssueLabels add labels to an issue. It will check if the labels are valid for the issue
-func newIssueLabels(e *xorm.Session, issue *Issue, labels []*Label, doer *User) (err error) {
+func newIssueLabels(e db.Engine, issue *Issue, labels []*Label, doer *User) (err error) {
 	if err = issue.loadRepo(e); err != nil {
 		return err
 	}
@@ -738,25 +744,25 @@ func newIssueLabels(e *xorm.Session, issue *Issue, labels []*Label, doer *User)
 
 // NewIssueLabels creates a list of issue-label relations.
 func NewIssueLabels(issue *Issue, labels []*Label, doer *User) (err error) {
-	sess := x.NewSession()
-	defer sess.Close()
-	if err = sess.Begin(); err != nil {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
 		return err
 	}
+	defer committer.Close()
 
-	if err = newIssueLabels(sess, issue, labels, doer); err != nil {
+	if err = newIssueLabels(ctx.Engine(), issue, labels, doer); err != nil {
 		return err
 	}
 
 	issue.Labels = nil
-	if err = issue.loadLabels(sess); err != nil {
+	if err = issue.loadLabels(ctx.Engine()); err != nil {
 		return err
 	}
 
-	return sess.Commit()
+	return committer.Commit()
 }
 
-func deleteIssueLabel(e *xorm.Session, issue *Issue, label *Label, doer *User) (err error) {
+func deleteIssueLabel(e db.Engine, issue *Issue, label *Label, doer *User) (err error) {
 	if count, err := e.Delete(&IssueLabel{
 		IssueID: issue.ID,
 		LabelID: label.ID,
@@ -786,7 +792,7 @@ func deleteIssueLabel(e *xorm.Session, issue *Issue, label *Label, doer *User) (
 
 // DeleteIssueLabel deletes issue-label relation.
 func DeleteIssueLabel(issue *Issue, label *Label, doer *User) (err error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -804,7 +810,7 @@ func DeleteIssueLabel(issue *Issue, label *Label, doer *User) (err error) {
 	return sess.Commit()
 }
 
-func deleteLabelsByRepoID(sess Engine, repoID int64) error {
+func deleteLabelsByRepoID(sess db.Engine, repoID int64) error {
 	deleteCond := builder.Select("id").From("label").Where(builder.Eq{"label.repo_id": repoID})
 
 	if _, err := sess.In("label_id", deleteCond).
diff --git a/models/issue_label_test.go b/models/issue_label_test.go
index 3dde1a406..384965b84 100644
--- a/models/issue_label_test.go
+++ b/models/issue_label_test.go
@@ -8,29 +8,30 @@ import (
 	"html/template"
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 // TODO TestGetLabelTemplateFile
 
 func TestLabel_CalOpenIssues(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	label := AssertExistsAndLoadBean(t, &Label{ID: 1}).(*Label)
+	assert.NoError(t, db.PrepareTestDatabase())
+	label := db.AssertExistsAndLoadBean(t, &Label{ID: 1}).(*Label)
 	label.CalOpenIssues()
 	assert.EqualValues(t, 2, label.NumOpenIssues)
 }
 
 func TestLabel_ForegroundColor(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	label := AssertExistsAndLoadBean(t, &Label{ID: 1}).(*Label)
+	assert.NoError(t, db.PrepareTestDatabase())
+	label := db.AssertExistsAndLoadBean(t, &Label{ID: 1}).(*Label)
 	assert.Equal(t, template.CSS("#000"), label.ForegroundColor())
 
-	label = AssertExistsAndLoadBean(t, &Label{ID: 2}).(*Label)
+	label = db.AssertExistsAndLoadBean(t, &Label{ID: 2}).(*Label)
 	assert.Equal(t, template.CSS("#fff"), label.ForegroundColor())
 }
 
 func TestNewLabels(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	labels := []*Label{
 		{RepoID: 2, Name: "labelName2", Color: "#123456"},
 		{RepoID: 3, Name: "labelName3", Color: "#23456F"},
@@ -39,27 +40,27 @@ func TestNewLabels(t *testing.T) {
 	assert.Error(t, NewLabel(&Label{RepoID: 3, Name: "invalid Color", Color: "123456"}))
 	assert.Error(t, NewLabel(&Label{RepoID: 3, Name: "invalid Color", Color: "#12345G"}))
 	for _, label := range labels {
-		AssertNotExistsBean(t, label)
+		db.AssertNotExistsBean(t, label)
 	}
 	assert.NoError(t, NewLabels(labels...))
 	for _, label := range labels {
-		AssertExistsAndLoadBean(t, label, Cond("id = ?", label.ID))
+		db.AssertExistsAndLoadBean(t, label, db.Cond("id = ?", label.ID))
 	}
 	CheckConsistencyFor(t, &Label{}, &Repository{})
 }
 
 func TestGetLabelByID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	label, err := GetLabelByID(1)
 	assert.NoError(t, err)
 	assert.EqualValues(t, 1, label.ID)
 
-	_, err = GetLabelByID(NonexistentID)
+	_, err = GetLabelByID(db.NonexistentID)
 	assert.True(t, IsErrLabelNotExist(err))
 }
 
 func TestGetLabelInRepoByName(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	label, err := GetLabelInRepoByName(1, "label1")
 	assert.NoError(t, err)
 	assert.EqualValues(t, 1, label.ID)
@@ -68,12 +69,12 @@ func TestGetLabelInRepoByName(t *testing.T) {
 	_, err = GetLabelInRepoByName(1, "")
 	assert.True(t, IsErrRepoLabelNotExist(err))
 
-	_, err = GetLabelInRepoByName(NonexistentID, "nonexistent")
+	_, err = GetLabelInRepoByName(db.NonexistentID, "nonexistent")
 	assert.True(t, IsErrRepoLabelNotExist(err))
 }
 
 func TestGetLabelInRepoByNames(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	labelIDs, err := GetLabelIDsInRepoByNames(1, []string{"label1", "label2"})
 	assert.NoError(t, err)
 
@@ -84,7 +85,7 @@ func TestGetLabelInRepoByNames(t *testing.T) {
 }
 
 func TestGetLabelInRepoByNamesDiscardsNonExistentLabels(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	// label3 doesn't exists.. See labels.yml
 	labelIDs, err := GetLabelIDsInRepoByNames(1, []string{"label1", "label2", "label3"})
 	assert.NoError(t, err)
@@ -97,7 +98,7 @@ func TestGetLabelInRepoByNamesDiscardsNonExistentLabels(t *testing.T) {
 }
 
 func TestGetLabelInRepoByID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	label, err := GetLabelInRepoByID(1, 1)
 	assert.NoError(t, err)
 	assert.EqualValues(t, 1, label.ID)
@@ -105,13 +106,13 @@ func TestGetLabelInRepoByID(t *testing.T) {
 	_, err = GetLabelInRepoByID(1, -1)
 	assert.True(t, IsErrRepoLabelNotExist(err))
 
-	_, err = GetLabelInRepoByID(NonexistentID, NonexistentID)
+	_, err = GetLabelInRepoByID(db.NonexistentID, db.NonexistentID)
 	assert.True(t, IsErrRepoLabelNotExist(err))
 }
 
 func TestGetLabelsInRepoByIDs(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	labels, err := GetLabelsInRepoByIDs(1, []int64{1, 2, NonexistentID})
+	assert.NoError(t, db.PrepareTestDatabase())
+	labels, err := GetLabelsInRepoByIDs(1, []int64{1, 2, db.NonexistentID})
 	assert.NoError(t, err)
 	if assert.Len(t, labels, 2) {
 		assert.EqualValues(t, 1, labels[0].ID)
@@ -120,7 +121,7 @@ func TestGetLabelsInRepoByIDs(t *testing.T) {
 }
 
 func TestGetLabelsByRepoID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	testSuccess := func(repoID int64, sortType string, expectedIssueIDs []int64) {
 		labels, err := GetLabelsByRepoID(repoID, sortType, ListOptions{})
 		assert.NoError(t, err)
@@ -138,7 +139,7 @@ func TestGetLabelsByRepoID(t *testing.T) {
 // Org versions
 
 func TestGetLabelInOrgByName(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	label, err := GetLabelInOrgByName(3, "orglabel3")
 	assert.NoError(t, err)
 	assert.EqualValues(t, 3, label.ID)
@@ -153,12 +154,12 @@ func TestGetLabelInOrgByName(t *testing.T) {
 	_, err = GetLabelInOrgByName(-1, "orglabel3")
 	assert.True(t, IsErrOrgLabelNotExist(err))
 
-	_, err = GetLabelInOrgByName(NonexistentID, "nonexistent")
+	_, err = GetLabelInOrgByName(db.NonexistentID, "nonexistent")
 	assert.True(t, IsErrOrgLabelNotExist(err))
 }
 
 func TestGetLabelInOrgByNames(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	labelIDs, err := GetLabelIDsInOrgByNames(3, []string{"orglabel3", "orglabel4"})
 	assert.NoError(t, err)
 
@@ -169,7 +170,7 @@ func TestGetLabelInOrgByNames(t *testing.T) {
 }
 
 func TestGetLabelInOrgByNamesDiscardsNonExistentLabels(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	// orglabel99 doesn't exists.. See labels.yml
 	labelIDs, err := GetLabelIDsInOrgByNames(3, []string{"orglabel3", "orglabel4", "orglabel99"})
 	assert.NoError(t, err)
@@ -182,7 +183,7 @@ func TestGetLabelInOrgByNamesDiscardsNonExistentLabels(t *testing.T) {
 }
 
 func TestGetLabelInOrgByID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	label, err := GetLabelInOrgByID(3, 3)
 	assert.NoError(t, err)
 	assert.EqualValues(t, 3, label.ID)
@@ -196,13 +197,13 @@ func TestGetLabelInOrgByID(t *testing.T) {
 	_, err = GetLabelInOrgByID(-1, 3)
 	assert.True(t, IsErrOrgLabelNotExist(err))
 
-	_, err = GetLabelInOrgByID(NonexistentID, NonexistentID)
+	_, err = GetLabelInOrgByID(db.NonexistentID, db.NonexistentID)
 	assert.True(t, IsErrOrgLabelNotExist(err))
 }
 
 func TestGetLabelsInOrgByIDs(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	labels, err := GetLabelsInOrgByIDs(3, []int64{3, 4, NonexistentID})
+	assert.NoError(t, db.PrepareTestDatabase())
+	labels, err := GetLabelsInOrgByIDs(3, []int64{3, 4, db.NonexistentID})
 	assert.NoError(t, err)
 	if assert.Len(t, labels, 2) {
 		assert.EqualValues(t, 3, labels[0].ID)
@@ -211,7 +212,7 @@ func TestGetLabelsInOrgByIDs(t *testing.T) {
 }
 
 func TestGetLabelsByOrgID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	testSuccess := func(orgID int64, sortType string, expectedIssueIDs []int64) {
 		labels, err := GetLabelsByOrgID(orgID, sortType, ListOptions{})
 		assert.NoError(t, err)
@@ -236,21 +237,21 @@ func TestGetLabelsByOrgID(t *testing.T) {
 //
 
 func TestGetLabelsByIssueID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	labels, err := GetLabelsByIssueID(1)
 	assert.NoError(t, err)
 	if assert.Len(t, labels, 1) {
 		assert.EqualValues(t, 1, labels[0].ID)
 	}
 
-	labels, err = GetLabelsByIssueID(NonexistentID)
+	labels, err = GetLabelsByIssueID(db.NonexistentID)
 	assert.NoError(t, err)
 	assert.Len(t, labels, 0)
 }
 
 func TestUpdateLabel(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	label := AssertExistsAndLoadBean(t, &Label{ID: 1}).(*Label)
+	assert.NoError(t, db.PrepareTestDatabase())
+	label := db.AssertExistsAndLoadBean(t, &Label{ID: 1}).(*Label)
 	// make sure update wont overwrite it
 	update := &Label{
 		ID:          label.ID,
@@ -261,7 +262,7 @@ func TestUpdateLabel(t *testing.T) {
 	label.Color = update.Color
 	label.Name = update.Name
 	assert.NoError(t, UpdateLabel(update))
-	newLabel := AssertExistsAndLoadBean(t, &Label{ID: 1}).(*Label)
+	newLabel := db.AssertExistsAndLoadBean(t, &Label{ID: 1}).(*Label)
 	assert.EqualValues(t, label.ID, newLabel.ID)
 	assert.EqualValues(t, label.Color, newLabel.Color)
 	assert.EqualValues(t, label.Name, newLabel.Name)
@@ -270,43 +271,43 @@ func TestUpdateLabel(t *testing.T) {
 }
 
 func TestDeleteLabel(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	label := AssertExistsAndLoadBean(t, &Label{ID: 1}).(*Label)
+	assert.NoError(t, db.PrepareTestDatabase())
+	label := db.AssertExistsAndLoadBean(t, &Label{ID: 1}).(*Label)
 	assert.NoError(t, DeleteLabel(label.RepoID, label.ID))
-	AssertNotExistsBean(t, &Label{ID: label.ID, RepoID: label.RepoID})
+	db.AssertNotExistsBean(t, &Label{ID: label.ID, RepoID: label.RepoID})
 
 	assert.NoError(t, DeleteLabel(label.RepoID, label.ID))
-	AssertNotExistsBean(t, &Label{ID: label.ID})
+	db.AssertNotExistsBean(t, &Label{ID: label.ID})
 
-	assert.NoError(t, DeleteLabel(NonexistentID, NonexistentID))
+	assert.NoError(t, DeleteLabel(db.NonexistentID, db.NonexistentID))
 	CheckConsistencyFor(t, &Label{}, &Repository{})
 }
 
 func TestHasIssueLabel(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	assert.True(t, HasIssueLabel(1, 1))
 	assert.False(t, HasIssueLabel(1, 2))
-	assert.False(t, HasIssueLabel(NonexistentID, NonexistentID))
+	assert.False(t, HasIssueLabel(db.NonexistentID, db.NonexistentID))
 }
 
 func TestNewIssueLabel(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	label := AssertExistsAndLoadBean(t, &Label{ID: 2}).(*Label)
-	issue := AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
-	doer := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	label := db.AssertExistsAndLoadBean(t, &Label{ID: 2}).(*Label)
+	issue := db.AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
+	doer := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 
 	// add new IssueLabel
 	prevNumIssues := label.NumIssues
 	assert.NoError(t, NewIssueLabel(issue, label, doer))
-	AssertExistsAndLoadBean(t, &IssueLabel{IssueID: issue.ID, LabelID: label.ID})
-	AssertExistsAndLoadBean(t, &Comment{
+	db.AssertExistsAndLoadBean(t, &IssueLabel{IssueID: issue.ID, LabelID: label.ID})
+	db.AssertExistsAndLoadBean(t, &Comment{
 		Type:     CommentTypeLabel,
 		PosterID: doer.ID,
 		IssueID:  issue.ID,
 		LabelID:  label.ID,
 		Content:  "1",
 	})
-	label = AssertExistsAndLoadBean(t, &Label{ID: 2}).(*Label)
+	label = db.AssertExistsAndLoadBean(t, &Label{ID: 2}).(*Label)
 	assert.EqualValues(t, prevNumIssues+1, label.NumIssues)
 
 	// re-add existing IssueLabel
@@ -315,26 +316,26 @@ func TestNewIssueLabel(t *testing.T) {
 }
 
 func TestNewIssueLabels(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	label1 := AssertExistsAndLoadBean(t, &Label{ID: 1}).(*Label)
-	label2 := AssertExistsAndLoadBean(t, &Label{ID: 2}).(*Label)
-	issue := AssertExistsAndLoadBean(t, &Issue{ID: 5}).(*Issue)
-	doer := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	label1 := db.AssertExistsAndLoadBean(t, &Label{ID: 1}).(*Label)
+	label2 := db.AssertExistsAndLoadBean(t, &Label{ID: 2}).(*Label)
+	issue := db.AssertExistsAndLoadBean(t, &Issue{ID: 5}).(*Issue)
+	doer := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 
 	assert.NoError(t, NewIssueLabels(issue, []*Label{label1, label2}, doer))
-	AssertExistsAndLoadBean(t, &IssueLabel{IssueID: issue.ID, LabelID: label1.ID})
-	AssertExistsAndLoadBean(t, &Comment{
+	db.AssertExistsAndLoadBean(t, &IssueLabel{IssueID: issue.ID, LabelID: label1.ID})
+	db.AssertExistsAndLoadBean(t, &Comment{
 		Type:     CommentTypeLabel,
 		PosterID: doer.ID,
 		IssueID:  issue.ID,
 		LabelID:  label1.ID,
 		Content:  "1",
 	})
-	AssertExistsAndLoadBean(t, &IssueLabel{IssueID: issue.ID, LabelID: label1.ID})
-	label1 = AssertExistsAndLoadBean(t, &Label{ID: 1}).(*Label)
+	db.AssertExistsAndLoadBean(t, &IssueLabel{IssueID: issue.ID, LabelID: label1.ID})
+	label1 = db.AssertExistsAndLoadBean(t, &Label{ID: 1}).(*Label)
 	assert.EqualValues(t, 3, label1.NumIssues)
 	assert.EqualValues(t, 1, label1.NumClosedIssues)
-	label2 = AssertExistsAndLoadBean(t, &Label{ID: 2}).(*Label)
+	label2 = db.AssertExistsAndLoadBean(t, &Label{ID: 2}).(*Label)
 	assert.EqualValues(t, 1, label2.NumIssues)
 	assert.EqualValues(t, 1, label2.NumClosedIssues)
 
@@ -345,15 +346,15 @@ func TestNewIssueLabels(t *testing.T) {
 }
 
 func TestDeleteIssueLabel(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	testSuccess := func(labelID, issueID, doerID int64) {
-		label := AssertExistsAndLoadBean(t, &Label{ID: labelID}).(*Label)
-		issue := AssertExistsAndLoadBean(t, &Issue{ID: issueID}).(*Issue)
-		doer := AssertExistsAndLoadBean(t, &User{ID: doerID}).(*User)
+		label := db.AssertExistsAndLoadBean(t, &Label{ID: labelID}).(*Label)
+		issue := db.AssertExistsAndLoadBean(t, &Issue{ID: issueID}).(*Issue)
+		doer := db.AssertExistsAndLoadBean(t, &User{ID: doerID}).(*User)
 
 		expectedNumIssues := label.NumIssues
 		expectedNumClosedIssues := label.NumClosedIssues
-		if BeanExists(t, &IssueLabel{IssueID: issueID, LabelID: labelID}) {
+		if db.BeanExists(t, &IssueLabel{IssueID: issueID, LabelID: labelID}) {
 			expectedNumIssues--
 			if issue.IsClosed {
 				expectedNumClosedIssues--
@@ -361,14 +362,14 @@ func TestDeleteIssueLabel(t *testing.T) {
 		}
 
 		assert.NoError(t, DeleteIssueLabel(issue, label, doer))
-		AssertNotExistsBean(t, &IssueLabel{IssueID: issueID, LabelID: labelID})
-		AssertExistsAndLoadBean(t, &Comment{
+		db.AssertNotExistsBean(t, &IssueLabel{IssueID: issueID, LabelID: labelID})
+		db.AssertExistsAndLoadBean(t, &Comment{
 			Type:     CommentTypeLabel,
 			PosterID: doerID,
 			IssueID:  issueID,
 			LabelID:  labelID,
 		}, `content=""`)
-		label = AssertExistsAndLoadBean(t, &Label{ID: labelID}).(*Label)
+		label = db.AssertExistsAndLoadBean(t, &Label{ID: labelID}).(*Label)
 		assert.EqualValues(t, expectedNumIssues, label.NumIssues)
 		assert.EqualValues(t, expectedNumClosedIssues, label.NumClosedIssues)
 	}
diff --git a/models/issue_list.go b/models/issue_list.go
index 87ad318dc..bac0803d8 100644
--- a/models/issue_list.go
+++ b/models/issue_list.go
@@ -7,6 +7,7 @@ package models
 import (
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"xorm.io/builder"
 )
 
@@ -28,7 +29,7 @@ func (issues IssueList) getRepoIDs() []int64 {
 	return keysInt64(repoIDs)
 }
 
-func (issues IssueList) loadRepositories(e Engine) ([]*Repository, error) {
+func (issues IssueList) loadRepositories(e db.Engine) ([]*Repository, error) {
 	if len(issues) == 0 {
 		return nil, nil
 	}
@@ -62,7 +63,7 @@ func (issues IssueList) loadRepositories(e Engine) ([]*Repository, error) {
 
 // LoadRepositories loads issues' all repositories
 func (issues IssueList) LoadRepositories() ([]*Repository, error) {
-	return issues.loadRepositories(x)
+	return issues.loadRepositories(db.DefaultContext().Engine())
 }
 
 func (issues IssueList) getPosterIDs() []int64 {
@@ -75,7 +76,7 @@ func (issues IssueList) getPosterIDs() []int64 {
 	return keysInt64(posterIDs)
 }
 
-func (issues IssueList) loadPosters(e Engine) error {
+func (issues IssueList) loadPosters(e db.Engine) error {
 	if len(issues) == 0 {
 		return nil
 	}
@@ -118,7 +119,7 @@ func (issues IssueList) getIssueIDs() []int64 {
 	return ids
 }
 
-func (issues IssueList) loadLabels(e Engine) error {
+func (issues IssueList) loadLabels(e db.Engine) error {
 	if len(issues) == 0 {
 		return nil
 	}
@@ -181,7 +182,7 @@ func (issues IssueList) getMilestoneIDs() []int64 {
 	return keysInt64(ids)
 }
 
-func (issues IssueList) loadMilestones(e Engine) error {
+func (issues IssueList) loadMilestones(e db.Engine) error {
 	milestoneIDs := issues.getMilestoneIDs()
 	if len(milestoneIDs) == 0 {
 		return nil
@@ -210,7 +211,7 @@ func (issues IssueList) loadMilestones(e Engine) error {
 	return nil
 }
 
-func (issues IssueList) loadAssignees(e Engine) error {
+func (issues IssueList) loadAssignees(e db.Engine) error {
 	if len(issues) == 0 {
 		return nil
 	}
@@ -271,7 +272,7 @@ func (issues IssueList) getPullIssueIDs() []int64 {
 	return ids
 }
 
-func (issues IssueList) loadPullRequests(e Engine) error {
+func (issues IssueList) loadPullRequests(e db.Engine) error {
 	issuesIDs := issues.getPullIssueIDs()
 	if len(issuesIDs) == 0 {
 		return nil
@@ -315,7 +316,7 @@ func (issues IssueList) loadPullRequests(e Engine) error {
 	return nil
 }
 
-func (issues IssueList) loadAttachments(e Engine) (err error) {
+func (issues IssueList) loadAttachments(e db.Engine) (err error) {
 	if len(issues) == 0 {
 		return nil
 	}
@@ -360,7 +361,7 @@ func (issues IssueList) loadAttachments(e Engine) (err error) {
 	return nil
 }
 
-func (issues IssueList) loadComments(e Engine, cond builder.Cond) (err error) {
+func (issues IssueList) loadComments(e db.Engine, cond builder.Cond) (err error) {
 	if len(issues) == 0 {
 		return nil
 	}
@@ -406,7 +407,7 @@ func (issues IssueList) loadComments(e Engine, cond builder.Cond) (err error) {
 	return nil
 }
 
-func (issues IssueList) loadTotalTrackedTimes(e Engine) (err error) {
+func (issues IssueList) loadTotalTrackedTimes(e db.Engine) (err error) {
 	type totalTimesByIssue struct {
 		IssueID int64
 		Time    int64
@@ -466,7 +467,7 @@ func (issues IssueList) loadTotalTrackedTimes(e Engine) (err error) {
 }
 
 // loadAttributes loads all attributes, expect for attachments and comments
-func (issues IssueList) loadAttributes(e Engine) error {
+func (issues IssueList) loadAttributes(e db.Engine) error {
 	if _, err := issues.loadRepositories(e); err != nil {
 		return fmt.Errorf("issue.loadAttributes: loadRepositories: %v", err)
 	}
@@ -501,36 +502,36 @@ func (issues IssueList) loadAttributes(e Engine) error {
 // LoadAttributes loads attributes of the issues, except for attachments and
 // comments
 func (issues IssueList) LoadAttributes() error {
-	return issues.loadAttributes(x)
+	return issues.loadAttributes(db.DefaultContext().Engine())
 }
 
 // LoadAttachments loads attachments
 func (issues IssueList) LoadAttachments() error {
-	return issues.loadAttachments(x)
+	return issues.loadAttachments(db.DefaultContext().Engine())
 }
 
 // LoadComments loads comments
 func (issues IssueList) LoadComments() error {
-	return issues.loadComments(x, builder.NewCond())
+	return issues.loadComments(db.DefaultContext().Engine(), builder.NewCond())
 }
 
 // LoadDiscussComments loads discuss comments
 func (issues IssueList) LoadDiscussComments() error {
-	return issues.loadComments(x, builder.Eq{"comment.type": CommentTypeComment})
+	return issues.loadComments(db.DefaultContext().Engine(), builder.Eq{"comment.type": CommentTypeComment})
 }
 
 // LoadPullRequests loads pull requests
 func (issues IssueList) LoadPullRequests() error {
-	return issues.loadPullRequests(x)
+	return issues.loadPullRequests(db.DefaultContext().Engine())
 }
 
 // GetApprovalCounts returns a map of issue ID to slice of approval counts
 // FIXME: only returns official counts due to double counting of non-official approvals
 func (issues IssueList) GetApprovalCounts() (map[int64][]*ReviewCount, error) {
-	return issues.getApprovalCounts(x)
+	return issues.getApprovalCounts(db.DefaultContext().Engine())
 }
 
-func (issues IssueList) getApprovalCounts(e Engine) (map[int64][]*ReviewCount, error) {
+func (issues IssueList) getApprovalCounts(e db.Engine) (map[int64][]*ReviewCount, error) {
 	rCounts := make([]*ReviewCount, 0, 2*len(issues))
 	ids := make([]int64, len(issues))
 	for i, issue := range issues {
diff --git a/models/issue_list_test.go b/models/issue_list_test.go
index c9c39332c..dadca3844 100644
--- a/models/issue_list_test.go
+++ b/models/issue_list_test.go
@@ -7,18 +7,19 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestIssueList_LoadRepositories(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	issueList := IssueList{
-		AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue),
-		AssertExistsAndLoadBean(t, &Issue{ID: 2}).(*Issue),
-		AssertExistsAndLoadBean(t, &Issue{ID: 4}).(*Issue),
+		db.AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue),
+		db.AssertExistsAndLoadBean(t, &Issue{ID: 2}).(*Issue),
+		db.AssertExistsAndLoadBean(t, &Issue{ID: 4}).(*Issue),
 	}
 
 	repos, err := issueList.LoadRepositories()
@@ -30,11 +31,11 @@ func TestIssueList_LoadRepositories(t *testing.T) {
 }
 
 func TestIssueList_LoadAttributes(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	setting.Service.EnableTimetracking = true
 	issueList := IssueList{
-		AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue),
-		AssertExistsAndLoadBean(t, &Issue{ID: 4}).(*Issue),
+		db.AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue),
+		db.AssertExistsAndLoadBean(t, &Issue{ID: 4}).(*Issue),
 	}
 
 	assert.NoError(t, issueList.LoadAttributes())
@@ -42,7 +43,7 @@ func TestIssueList_LoadAttributes(t *testing.T) {
 		assert.EqualValues(t, issue.RepoID, issue.Repo.ID)
 		for _, label := range issue.Labels {
 			assert.EqualValues(t, issue.RepoID, label.RepoID)
-			AssertExistsAndLoadBean(t, &IssueLabel{IssueID: issue.ID, LabelID: label.ID})
+			db.AssertExistsAndLoadBean(t, &IssueLabel{IssueID: issue.ID, LabelID: label.ID})
 		}
 		if issue.PosterID > 0 {
 			assert.EqualValues(t, issue.PosterID, issue.Poster.ID)
diff --git a/models/issue_lock.go b/models/issue_lock.go
index 78b2c5cdb..f7474bfd1 100644
--- a/models/issue_lock.go
+++ b/models/issue_lock.go
@@ -4,6 +4,8 @@
 
 package models
 
+import "code.gitea.io/gitea/models/db"
+
 // IssueLockOptions defines options for locking and/or unlocking an issue/PR
 type IssueLockOptions struct {
 	Doer   *User
@@ -35,7 +37,7 @@ func updateIssueLock(opts *IssueLockOptions, lock bool) error {
 		commentType = CommentTypeUnlock
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
diff --git a/models/issue_milestone.go b/models/issue_milestone.go
index cfd11c5fa..da321911f 100644
--- a/models/issue_milestone.go
+++ b/models/issue_milestone.go
@@ -9,6 +9,7 @@ import (
 	"strings"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/timeutil"
@@ -42,6 +43,10 @@ type Milestone struct {
 	TimeSinceUpdate  int64 `xorm:"-"`
 }
 
+func init() {
+	db.RegisterModel(new(Milestone))
+}
+
 // BeforeUpdate is invoked from XORM before updating this object.
 func (m *Milestone) BeforeUpdate() {
 	if m.NumIssues > 0 {
@@ -80,7 +85,7 @@ func (m *Milestone) State() api.StateType {
 
 // NewMilestone creates new milestone of repository.
 func NewMilestone(m *Milestone) (err error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -98,7 +103,7 @@ func NewMilestone(m *Milestone) (err error) {
 	return sess.Commit()
 }
 
-func getMilestoneByRepoID(e Engine, repoID, id int64) (*Milestone, error) {
+func getMilestoneByRepoID(e db.Engine, repoID, id int64) (*Milestone, error) {
 	m := new(Milestone)
 	has, err := e.ID(id).Where("repo_id=?", repoID).Get(m)
 	if err != nil {
@@ -111,13 +116,13 @@ func getMilestoneByRepoID(e Engine, repoID, id int64) (*Milestone, error) {
 
 // GetMilestoneByRepoID returns the milestone in a repository.
 func GetMilestoneByRepoID(repoID, id int64) (*Milestone, error) {
-	return getMilestoneByRepoID(x, repoID, id)
+	return getMilestoneByRepoID(db.DefaultContext().Engine(), repoID, id)
 }
 
 // GetMilestoneByRepoIDANDName return a milestone if one exist by name and repo
 func GetMilestoneByRepoIDANDName(repoID int64, name string) (*Milestone, error) {
 	var mile Milestone
-	has, err := x.Where("repo_id=? AND name=?", repoID, name).Get(&mile)
+	has, err := db.DefaultContext().Engine().Where("repo_id=? AND name=?", repoID, name).Get(&mile)
 	if err != nil {
 		return nil, err
 	}
@@ -129,10 +134,10 @@ func GetMilestoneByRepoIDANDName(repoID int64, name string) (*Milestone, error)
 
 // GetMilestoneByID returns the milestone via id .
 func GetMilestoneByID(id int64) (*Milestone, error) {
-	return getMilestoneByID(x, id)
+	return getMilestoneByID(db.DefaultContext().Engine(), id)
 }
 
-func getMilestoneByID(e Engine, id int64) (*Milestone, error) {
+func getMilestoneByID(e db.Engine, id int64) (*Milestone, error) {
 	var m Milestone
 	has, err := e.ID(id).Get(&m)
 	if err != nil {
@@ -145,7 +150,7 @@ func getMilestoneByID(e Engine, id int64) (*Milestone, error) {
 
 // UpdateMilestone updates information of given milestone.
 func UpdateMilestone(m *Milestone, oldIsClosed bool) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -169,7 +174,7 @@ func UpdateMilestone(m *Milestone, oldIsClosed bool) error {
 	return sess.Commit()
 }
 
-func updateMilestone(e Engine, m *Milestone) error {
+func updateMilestone(e db.Engine, m *Milestone) error {
 	m.Name = strings.TrimSpace(m.Name)
 	_, err := e.ID(m.ID).AllCols().Update(m)
 	if err != nil {
@@ -179,7 +184,7 @@ func updateMilestone(e Engine, m *Milestone) error {
 }
 
 // updateMilestoneCounters calculates NumIssues, NumClosesIssues and Completeness
-func updateMilestoneCounters(e Engine, id int64) error {
+func updateMilestoneCounters(e db.Engine, id int64) error {
 	_, err := e.ID(id).
 		SetExpr("num_issues", builder.Select("count(*)").From("issue").Where(
 			builder.Eq{"milestone_id": id},
@@ -202,7 +207,7 @@ func updateMilestoneCounters(e Engine, id int64) error {
 
 // ChangeMilestoneStatusByRepoIDAndID changes a milestone open/closed status if the milestone ID is in the repo.
 func ChangeMilestoneStatusByRepoIDAndID(repoID, milestoneID int64, isClosed bool) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -229,7 +234,7 @@ func ChangeMilestoneStatusByRepoIDAndID(repoID, milestoneID int64, isClosed bool
 
 // ChangeMilestoneStatus changes the milestone open/closed status.
 func ChangeMilestoneStatus(m *Milestone, isClosed bool) (err error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -242,7 +247,7 @@ func ChangeMilestoneStatus(m *Milestone, isClosed bool) (err error) {
 	return sess.Commit()
 }
 
-func changeMilestoneStatus(e Engine, m *Milestone, isClosed bool) error {
+func changeMilestoneStatus(e db.Engine, m *Milestone, isClosed bool) error {
 	m.IsClosed = isClosed
 	if isClosed {
 		m.ClosedDateUnix = timeutil.TimeStampNow()
@@ -298,7 +303,7 @@ func changeMilestoneAssign(e *xorm.Session, doer *User, issue *Issue, oldMilesto
 
 // ChangeMilestoneAssign changes assignment of milestone for issue.
 func ChangeMilestoneAssign(issue *Issue, doer *User, oldMilestoneID int64) (err error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -329,7 +334,7 @@ func DeleteMilestoneByRepoID(repoID, id int64) error {
 		return err
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -405,7 +410,7 @@ func (opts GetMilestonesOption) toCond() builder.Cond {
 
 // GetMilestones returns milestones filtered by GetMilestonesOption's
 func GetMilestones(opts GetMilestonesOption) (MilestoneList, int64, error) {
-	sess := x.Where(opts.toCond())
+	sess := db.DefaultContext().Engine().Where(opts.toCond())
 
 	if opts.Page != 0 {
 		sess = setSessionPagination(sess, &opts)
@@ -436,7 +441,7 @@ func GetMilestones(opts GetMilestonesOption) (MilestoneList, int64, error) {
 // SearchMilestones search milestones
 func SearchMilestones(repoCond builder.Cond, page int, isClosed bool, sortType string, keyword string) (MilestoneList, error) {
 	miles := make([]*Milestone, 0, setting.UI.IssuePagingNum)
-	sess := x.Where("is_closed = ?", isClosed)
+	sess := db.DefaultContext().Engine().Where("is_closed = ?", isClosed)
 	if len(keyword) > 0 {
 		sess = sess.And(builder.Like{"UPPER(name)", strings.ToUpper(keyword)})
 	}
@@ -497,7 +502,7 @@ func GetMilestonesStatsByRepoCond(repoCond builder.Cond) (*MilestonesStats, erro
 	var err error
 	stats := &MilestonesStats{}
 
-	sess := x.Where("is_closed = ?", false)
+	sess := db.DefaultContext().Engine().Where("is_closed = ?", false)
 	if repoCond.IsValid() {
 		sess.And(builder.In("repo_id", builder.Select("id").From("repository").Where(repoCond)))
 	}
@@ -506,7 +511,7 @@ func GetMilestonesStatsByRepoCond(repoCond builder.Cond) (*MilestonesStats, erro
 		return nil, err
 	}
 
-	sess = x.Where("is_closed = ?", true)
+	sess = db.DefaultContext().Engine().Where("is_closed = ?", true)
 	if repoCond.IsValid() {
 		sess.And(builder.In("repo_id", builder.Select("id").From("repository").Where(repoCond)))
 	}
@@ -523,7 +528,7 @@ func GetMilestonesStatsByRepoCondAndKw(repoCond builder.Cond, keyword string) (*
 	var err error
 	stats := &MilestonesStats{}
 
-	sess := x.Where("is_closed = ?", false)
+	sess := db.DefaultContext().Engine().Where("is_closed = ?", false)
 	if len(keyword) > 0 {
 		sess = sess.And(builder.Like{"UPPER(name)", strings.ToUpper(keyword)})
 	}
@@ -535,7 +540,7 @@ func GetMilestonesStatsByRepoCondAndKw(repoCond builder.Cond, keyword string) (*
 		return nil, err
 	}
 
-	sess = x.Where("is_closed = ?", true)
+	sess = db.DefaultContext().Engine().Where("is_closed = ?", true)
 	if len(keyword) > 0 {
 		sess = sess.And(builder.Like{"UPPER(name)", strings.ToUpper(keyword)})
 	}
@@ -550,13 +555,13 @@ func GetMilestonesStatsByRepoCondAndKw(repoCond builder.Cond, keyword string) (*
 	return stats, nil
 }
 
-func countRepoMilestones(e Engine, repoID int64) (int64, error) {
+func countRepoMilestones(e db.Engine, repoID int64) (int64, error) {
 	return e.
 		Where("repo_id=?", repoID).
 		Count(new(Milestone))
 }
 
-func countRepoClosedMilestones(e Engine, repoID int64) (int64, error) {
+func countRepoClosedMilestones(e db.Engine, repoID int64) (int64, error) {
 	return e.
 		Where("repo_id=? AND is_closed=?", repoID, true).
 		Count(new(Milestone))
@@ -564,12 +569,12 @@ func countRepoClosedMilestones(e Engine, repoID int64) (int64, error) {
 
 // CountRepoClosedMilestones returns number of closed milestones in given repository.
 func CountRepoClosedMilestones(repoID int64) (int64, error) {
-	return countRepoClosedMilestones(x, repoID)
+	return countRepoClosedMilestones(db.DefaultContext().Engine(), repoID)
 }
 
 // CountMilestonesByRepoCond map from repo conditions to number of milestones matching the options`
 func CountMilestonesByRepoCond(repoCond builder.Cond, isClosed bool) (map[int64]int64, error) {
-	sess := x.Where("is_closed = ?", isClosed)
+	sess := db.DefaultContext().Engine().Where("is_closed = ?", isClosed)
 	if repoCond.IsValid() {
 		sess.In("repo_id", builder.Select("id").From("repository").Where(repoCond))
 	}
@@ -594,7 +599,7 @@ func CountMilestonesByRepoCond(repoCond builder.Cond, isClosed bool) (map[int64]
 
 // CountMilestonesByRepoCondAndKw map from repo conditions and the keyword of milestones' name to number of milestones matching the options`
 func CountMilestonesByRepoCondAndKw(repoCond builder.Cond, keyword string, isClosed bool) (map[int64]int64, error) {
-	sess := x.Where("is_closed = ?", isClosed)
+	sess := db.DefaultContext().Engine().Where("is_closed = ?", isClosed)
 	if len(keyword) > 0 {
 		sess = sess.And(builder.Like{"UPPER(name)", strings.ToUpper(keyword)})
 	}
@@ -620,7 +625,7 @@ func CountMilestonesByRepoCondAndKw(repoCond builder.Cond, keyword string, isClo
 	return countMap, nil
 }
 
-func updateRepoMilestoneNum(e Engine, repoID int64) error {
+func updateRepoMilestoneNum(e db.Engine, repoID int64) error {
 	_, err := e.Exec("UPDATE `repository` SET num_milestones=(SELECT count(*) FROM milestone WHERE repo_id=?),num_closed_milestones=(SELECT count(*) FROM milestone WHERE repo_id=? AND is_closed=?) WHERE id=?",
 		repoID,
 		repoID,
@@ -637,7 +642,7 @@ func updateRepoMilestoneNum(e Engine, repoID int64) error {
 //   |_||_|  \__,_|\___|_|\_\___|\__,_| |_| |_|_| |_| |_|\___||___/
 //
 
-func (milestones MilestoneList) loadTotalTrackedTimes(e Engine) error {
+func (milestones MilestoneList) loadTotalTrackedTimes(e db.Engine) error {
 	type totalTimesByMilestone struct {
 		MilestoneID int64
 		Time        int64
@@ -677,7 +682,7 @@ func (milestones MilestoneList) loadTotalTrackedTimes(e Engine) error {
 	return nil
 }
 
-func (m *Milestone) loadTotalTrackedTime(e Engine) error {
+func (m *Milestone) loadTotalTrackedTime(e db.Engine) error {
 	type totalTimesByMilestone struct {
 		MilestoneID int64
 		Time        int64
@@ -702,10 +707,10 @@ func (m *Milestone) loadTotalTrackedTime(e Engine) error {
 
 // LoadTotalTrackedTimes loads for every milestone in the list the TotalTrackedTime by a batch request
 func (milestones MilestoneList) LoadTotalTrackedTimes() error {
-	return milestones.loadTotalTrackedTimes(x)
+	return milestones.loadTotalTrackedTimes(db.DefaultContext().Engine())
 }
 
 // LoadTotalTrackedTime loads the tracked time for the milestone
 func (m *Milestone) LoadTotalTrackedTime() error {
-	return m.loadTotalTrackedTime(x)
+	return m.loadTotalTrackedTime(db.DefaultContext().Engine())
 }
diff --git a/models/issue_milestone_test.go b/models/issue_milestone_test.go
index 1472c951e..fd12efb14 100644
--- a/models/issue_milestone_test.go
+++ b/models/issue_milestone_test.go
@@ -8,6 +8,7 @@ import (
 	"sort"
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/timeutil"
@@ -22,7 +23,7 @@ func TestMilestone_State(t *testing.T) {
 }
 
 func TestNewMilestone(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	milestone := &Milestone{
 		RepoID:  1,
 		Name:    "milestoneName",
@@ -30,26 +31,26 @@ func TestNewMilestone(t *testing.T) {
 	}
 
 	assert.NoError(t, NewMilestone(milestone))
-	AssertExistsAndLoadBean(t, milestone)
+	db.AssertExistsAndLoadBean(t, milestone)
 	CheckConsistencyFor(t, &Repository{ID: milestone.RepoID}, &Milestone{})
 }
 
 func TestGetMilestoneByRepoID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	milestone, err := GetMilestoneByRepoID(1, 1)
 	assert.NoError(t, err)
 	assert.EqualValues(t, 1, milestone.ID)
 	assert.EqualValues(t, 1, milestone.RepoID)
 
-	_, err = GetMilestoneByRepoID(NonexistentID, NonexistentID)
+	_, err = GetMilestoneByRepoID(db.NonexistentID, db.NonexistentID)
 	assert.True(t, IsErrMilestoneNotExist(err))
 }
 
 func TestGetMilestonesByRepoID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	test := func(repoID int64, state api.StateType) {
-		repo := AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
+		repo := db.AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
 		milestones, _, err := GetMilestones(GetMilestonesOption{
 			RepoID: repo.ID,
 			State:  state,
@@ -88,7 +89,7 @@ func TestGetMilestonesByRepoID(t *testing.T) {
 	test(3, api.StateAll)
 
 	milestones, _, err := GetMilestones(GetMilestonesOption{
-		RepoID: NonexistentID,
+		RepoID: db.NonexistentID,
 		State:  api.StateOpen,
 	})
 	assert.NoError(t, err)
@@ -96,8 +97,8 @@ func TestGetMilestonesByRepoID(t *testing.T) {
 }
 
 func TestGetMilestones(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	assert.NoError(t, db.PrepareTestDatabase())
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
 	test := func(sortType string, sortCond func(*Milestone) int) {
 		for _, page := range []int{0, 1} {
 			milestones, _, err := GetMilestones(GetMilestonesOption{
@@ -157,22 +158,22 @@ func TestGetMilestones(t *testing.T) {
 }
 
 func TestUpdateMilestone(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	milestone := AssertExistsAndLoadBean(t, &Milestone{ID: 1}).(*Milestone)
+	milestone := db.AssertExistsAndLoadBean(t, &Milestone{ID: 1}).(*Milestone)
 	milestone.Name = " newMilestoneName  "
 	milestone.Content = "newMilestoneContent"
 	assert.NoError(t, UpdateMilestone(milestone, milestone.IsClosed))
-	milestone = AssertExistsAndLoadBean(t, &Milestone{ID: 1}).(*Milestone)
+	milestone = db.AssertExistsAndLoadBean(t, &Milestone{ID: 1}).(*Milestone)
 	assert.EqualValues(t, "newMilestoneName", milestone.Name)
 	CheckConsistencyFor(t, &Milestone{})
 }
 
 func TestCountRepoMilestones(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	test := func(repoID int64) {
-		repo := AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
-		count, err := countRepoMilestones(x, repoID)
+		repo := db.AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
+		count, err := countRepoMilestones(db.DefaultContext().Engine(), repoID)
 		assert.NoError(t, err)
 		assert.EqualValues(t, repo.NumMilestones, count)
 	}
@@ -180,15 +181,15 @@ func TestCountRepoMilestones(t *testing.T) {
 	test(2)
 	test(3)
 
-	count, err := countRepoMilestones(x, NonexistentID)
+	count, err := countRepoMilestones(db.DefaultContext().Engine(), db.NonexistentID)
 	assert.NoError(t, err)
 	assert.EqualValues(t, 0, count)
 }
 
 func TestCountRepoClosedMilestones(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	test := func(repoID int64) {
-		repo := AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
+		repo := db.AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
 		count, err := CountRepoClosedMilestones(repoID)
 		assert.NoError(t, err)
 		assert.EqualValues(t, repo.NumClosedMilestones, count)
@@ -197,55 +198,55 @@ func TestCountRepoClosedMilestones(t *testing.T) {
 	test(2)
 	test(3)
 
-	count, err := CountRepoClosedMilestones(NonexistentID)
+	count, err := CountRepoClosedMilestones(db.NonexistentID)
 	assert.NoError(t, err)
 	assert.EqualValues(t, 0, count)
 }
 
 func TestChangeMilestoneStatus(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	milestone := AssertExistsAndLoadBean(t, &Milestone{ID: 1}).(*Milestone)
+	assert.NoError(t, db.PrepareTestDatabase())
+	milestone := db.AssertExistsAndLoadBean(t, &Milestone{ID: 1}).(*Milestone)
 
 	assert.NoError(t, ChangeMilestoneStatus(milestone, true))
-	AssertExistsAndLoadBean(t, &Milestone{ID: 1}, "is_closed=1")
+	db.AssertExistsAndLoadBean(t, &Milestone{ID: 1}, "is_closed=1")
 	CheckConsistencyFor(t, &Repository{ID: milestone.RepoID}, &Milestone{})
 
 	assert.NoError(t, ChangeMilestoneStatus(milestone, false))
-	AssertExistsAndLoadBean(t, &Milestone{ID: 1}, "is_closed=0")
+	db.AssertExistsAndLoadBean(t, &Milestone{ID: 1}, "is_closed=0")
 	CheckConsistencyFor(t, &Repository{ID: milestone.RepoID}, &Milestone{})
 }
 
 func TestUpdateMilestoneCounters(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	issue := AssertExistsAndLoadBean(t, &Issue{MilestoneID: 1},
+	assert.NoError(t, db.PrepareTestDatabase())
+	issue := db.AssertExistsAndLoadBean(t, &Issue{MilestoneID: 1},
 		"is_closed=0").(*Issue)
 
 	issue.IsClosed = true
 	issue.ClosedUnix = timeutil.TimeStampNow()
-	_, err := x.ID(issue.ID).Cols("is_closed", "closed_unix").Update(issue)
+	_, err := db.DefaultContext().Engine().ID(issue.ID).Cols("is_closed", "closed_unix").Update(issue)
 	assert.NoError(t, err)
-	assert.NoError(t, updateMilestoneCounters(x, issue.MilestoneID))
+	assert.NoError(t, updateMilestoneCounters(db.DefaultContext().Engine(), issue.MilestoneID))
 	CheckConsistencyFor(t, &Milestone{})
 
 	issue.IsClosed = false
 	issue.ClosedUnix = 0
-	_, err = x.ID(issue.ID).Cols("is_closed", "closed_unix").Update(issue)
+	_, err = db.DefaultContext().Engine().ID(issue.ID).Cols("is_closed", "closed_unix").Update(issue)
 	assert.NoError(t, err)
-	assert.NoError(t, updateMilestoneCounters(x, issue.MilestoneID))
+	assert.NoError(t, updateMilestoneCounters(db.DefaultContext().Engine(), issue.MilestoneID))
 	CheckConsistencyFor(t, &Milestone{})
 }
 
 func TestChangeMilestoneAssign(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	issue := AssertExistsAndLoadBean(t, &Issue{RepoID: 1}).(*Issue)
-	doer := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	issue := db.AssertExistsAndLoadBean(t, &Issue{RepoID: 1}).(*Issue)
+	doer := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	assert.NotNil(t, issue)
 	assert.NotNil(t, doer)
 
 	oldMilestoneID := issue.MilestoneID
 	issue.MilestoneID = 2
 	assert.NoError(t, ChangeMilestoneAssign(issue, doer, oldMilestoneID))
-	AssertExistsAndLoadBean(t, &Comment{
+	db.AssertExistsAndLoadBean(t, &Comment{
 		IssueID:        issue.ID,
 		Type:           CommentTypeMilestone,
 		MilestoneID:    issue.MilestoneID,
@@ -255,18 +256,18 @@ func TestChangeMilestoneAssign(t *testing.T) {
 }
 
 func TestDeleteMilestoneByRepoID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	assert.NoError(t, DeleteMilestoneByRepoID(1, 1))
-	AssertNotExistsBean(t, &Milestone{ID: 1})
+	db.AssertNotExistsBean(t, &Milestone{ID: 1})
 	CheckConsistencyFor(t, &Repository{ID: 1})
 
-	assert.NoError(t, DeleteMilestoneByRepoID(NonexistentID, NonexistentID))
+	assert.NoError(t, DeleteMilestoneByRepoID(db.NonexistentID, db.NonexistentID))
 }
 
 func TestMilestoneList_LoadTotalTrackedTimes(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	miles := MilestoneList{
-		AssertExistsAndLoadBean(t, &Milestone{ID: 1}).(*Milestone),
+		db.AssertExistsAndLoadBean(t, &Milestone{ID: 1}).(*Milestone),
 	}
 
 	assert.NoError(t, miles.LoadTotalTrackedTimes())
@@ -275,9 +276,9 @@ func TestMilestoneList_LoadTotalTrackedTimes(t *testing.T) {
 }
 
 func TestCountMilestonesByRepoIDs(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	milestonesCount := func(repoID int64) (int, int) {
-		repo := AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
+		repo := db.AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
 		return repo.NumOpenMilestones, repo.NumClosedMilestones
 	}
 	repo1OpenCount, repo1ClosedCount := milestonesCount(1)
@@ -295,9 +296,9 @@ func TestCountMilestonesByRepoIDs(t *testing.T) {
 }
 
 func TestGetMilestonesByRepoIDs(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	repo1 := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
-	repo2 := AssertExistsAndLoadBean(t, &Repository{ID: 2}).(*Repository)
+	assert.NoError(t, db.PrepareTestDatabase())
+	repo1 := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	repo2 := db.AssertExistsAndLoadBean(t, &Repository{ID: 2}).(*Repository)
 	test := func(sortType string, sortCond func(*Milestone) int) {
 		for _, page := range []int{0, 1} {
 			openMilestones, err := GetMilestonesByRepoIDs([]int64{repo1.ID, repo2.ID}, page, false, sortType)
@@ -340,8 +341,8 @@ func TestGetMilestonesByRepoIDs(t *testing.T) {
 }
 
 func TestLoadTotalTrackedTime(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	milestone := AssertExistsAndLoadBean(t, &Milestone{ID: 1}).(*Milestone)
+	assert.NoError(t, db.PrepareTestDatabase())
+	milestone := db.AssertExistsAndLoadBean(t, &Milestone{ID: 1}).(*Milestone)
 
 	assert.NoError(t, milestone.LoadTotalTrackedTime())
 
@@ -349,10 +350,10 @@ func TestLoadTotalTrackedTime(t *testing.T) {
 }
 
 func TestGetMilestonesStats(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	test := func(repoID int64) {
-		repo := AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
+		repo := db.AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
 		stats, err := GetMilestonesStatsByRepoCond(builder.And(builder.Eq{"repo_id": repoID}))
 		assert.NoError(t, err)
 		assert.EqualValues(t, repo.NumMilestones-repo.NumClosedMilestones, stats.OpenCount)
@@ -362,13 +363,13 @@ func TestGetMilestonesStats(t *testing.T) {
 	test(2)
 	test(3)
 
-	stats, err := GetMilestonesStatsByRepoCond(builder.And(builder.Eq{"repo_id": NonexistentID}))
+	stats, err := GetMilestonesStatsByRepoCond(builder.And(builder.Eq{"repo_id": db.NonexistentID}))
 	assert.NoError(t, err)
 	assert.EqualValues(t, 0, stats.OpenCount)
 	assert.EqualValues(t, 0, stats.ClosedCount)
 
-	repo1 := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
-	repo2 := AssertExistsAndLoadBean(t, &Repository{ID: 2}).(*Repository)
+	repo1 := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	repo2 := db.AssertExistsAndLoadBean(t, &Repository{ID: 2}).(*Repository)
 
 	milestoneStats, err := GetMilestonesStatsByRepoCond(builder.In("repo_id", []int64{repo1.ID, repo2.ID}))
 	assert.NoError(t, err)
diff --git a/models/issue_reaction.go b/models/issue_reaction.go
index 5721d8cc1..8fd22f6ca 100644
--- a/models/issue_reaction.go
+++ b/models/issue_reaction.go
@@ -8,6 +8,7 @@ import (
 	"bytes"
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/timeutil"
 
@@ -28,6 +29,10 @@ type Reaction struct {
 	CreatedUnix      timeutil.TimeStamp `xorm:"INDEX created"`
 }
 
+func init() {
+	db.RegisterModel(new(Reaction))
+}
+
 // FindReactionsOptions describes the conditions to Find reactions
 type FindReactionsOptions struct {
 	ListOptions
@@ -66,7 +71,7 @@ func (opts *FindReactionsOptions) toConds() builder.Cond {
 
 // FindCommentReactions returns a ReactionList of all reactions from an comment
 func FindCommentReactions(comment *Comment) (ReactionList, error) {
-	return findReactions(x, FindReactionsOptions{
+	return findReactions(db.DefaultContext().Engine(), FindReactionsOptions{
 		IssueID:   comment.IssueID,
 		CommentID: comment.ID,
 	})
@@ -74,14 +79,14 @@ func FindCommentReactions(comment *Comment) (ReactionList, error) {
 
 // FindIssueReactions returns a ReactionList of all reactions from an issue
 func FindIssueReactions(issue *Issue, listOptions ListOptions) (ReactionList, error) {
-	return findReactions(x, FindReactionsOptions{
+	return findReactions(db.DefaultContext().Engine(), FindReactionsOptions{
 		ListOptions: listOptions,
 		IssueID:     issue.ID,
 		CommentID:   -1,
 	})
 }
 
-func findReactions(e Engine, opts FindReactionsOptions) ([]*Reaction, error) {
+func findReactions(e db.Engine, opts FindReactionsOptions) ([]*Reaction, error) {
 	e = e.
 		Where(opts.toConds()).
 		In("reaction.`type`", setting.UI.Reactions).
@@ -143,7 +148,7 @@ func CreateReaction(opts *ReactionOptions) (*Reaction, error) {
 		return nil, ErrForbiddenIssueReaction{opts.Type}
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return nil, err
@@ -179,7 +184,7 @@ func CreateCommentReaction(doer *User, issue *Issue, comment *Comment, content s
 	})
 }
 
-func deleteReaction(e Engine, opts *ReactionOptions) error {
+func deleteReaction(e db.Engine, opts *ReactionOptions) error {
 	reaction := &Reaction{
 		Type: opts.Type,
 	}
@@ -198,7 +203,7 @@ func deleteReaction(e Engine, opts *ReactionOptions) error {
 
 // DeleteReaction deletes reaction for issue or comment.
 func DeleteReaction(opts *ReactionOptions) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -235,7 +240,7 @@ func (r *Reaction) LoadUser() (*User, error) {
 	if r.User != nil {
 		return r.User, nil
 	}
-	user, err := getUserByID(x, r.UserID)
+	user, err := getUserByID(db.DefaultContext().Engine(), r.UserID)
 	if err != nil {
 		return nil, err
 	}
@@ -281,7 +286,7 @@ func (list ReactionList) getUserIDs() []int64 {
 	return keysInt64(userIDs)
 }
 
-func (list ReactionList) loadUsers(e Engine, repo *Repository) ([]*User, error) {
+func (list ReactionList) loadUsers(e db.Engine, repo *Repository) ([]*User, error) {
 	if len(list) == 0 {
 		return nil, nil
 	}
@@ -309,7 +314,7 @@ func (list ReactionList) loadUsers(e Engine, repo *Repository) ([]*User, error)
 
 // LoadUsers loads reactions' all users
 func (list ReactionList) LoadUsers(repo *Repository) ([]*User, error) {
-	return list.loadUsers(x, repo)
+	return list.loadUsers(db.DefaultContext().Engine(), repo)
 }
 
 // GetFirstUsers returns first reacted user display names separated by comma
diff --git a/models/issue_reaction_test.go b/models/issue_reaction_test.go
index e7aa45e4c..b74d0ce9b 100644
--- a/models/issue_reaction_test.go
+++ b/models/issue_reaction_test.go
@@ -6,6 +6,7 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 
 	"github.com/stretchr/testify/assert"
@@ -24,23 +25,23 @@ func addReaction(t *testing.T, doer *User, issue *Issue, comment *Comment, conte
 }
 
 func TestIssueAddReaction(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user1 := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	user1 := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 
-	issue1 := AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
+	issue1 := db.AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
 
 	addReaction(t, user1, issue1, nil, "heart")
 
-	AssertExistsAndLoadBean(t, &Reaction{Type: "heart", UserID: user1.ID, IssueID: issue1.ID})
+	db.AssertExistsAndLoadBean(t, &Reaction{Type: "heart", UserID: user1.ID, IssueID: issue1.ID})
 }
 
 func TestIssueAddDuplicateReaction(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user1 := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	user1 := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 
-	issue1 := AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
+	issue1 := db.AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
 
 	addReaction(t, user1, issue1, nil, "heart")
 
@@ -52,37 +53,37 @@ func TestIssueAddDuplicateReaction(t *testing.T) {
 	assert.Error(t, err)
 	assert.Equal(t, ErrReactionAlreadyExist{Reaction: "heart"}, err)
 
-	existingR := AssertExistsAndLoadBean(t, &Reaction{Type: "heart", UserID: user1.ID, IssueID: issue1.ID}).(*Reaction)
+	existingR := db.AssertExistsAndLoadBean(t, &Reaction{Type: "heart", UserID: user1.ID, IssueID: issue1.ID}).(*Reaction)
 	assert.Equal(t, existingR.ID, reaction.ID)
 }
 
 func TestIssueDeleteReaction(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user1 := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	user1 := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 
-	issue1 := AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
+	issue1 := db.AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
 
 	addReaction(t, user1, issue1, nil, "heart")
 
 	err := DeleteIssueReaction(user1, issue1, "heart")
 	assert.NoError(t, err)
 
-	AssertNotExistsBean(t, &Reaction{Type: "heart", UserID: user1.ID, IssueID: issue1.ID})
+	db.AssertNotExistsBean(t, &Reaction{Type: "heart", UserID: user1.ID, IssueID: issue1.ID})
 }
 
 func TestIssueReactionCount(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	setting.UI.ReactionMaxUserNum = 2
 
-	user1 := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
-	user2 := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
-	user3 := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
-	user4 := AssertExistsAndLoadBean(t, &User{ID: 4}).(*User)
+	user1 := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	user2 := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user3 := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	user4 := db.AssertExistsAndLoadBean(t, &User{ID: 4}).(*User)
 	ghost := NewGhostUser()
 
-	issue := AssertExistsAndLoadBean(t, &Issue{ID: 2}).(*Issue)
+	issue := db.AssertExistsAndLoadBean(t, &Issue{ID: 2}).(*Issue)
 
 	addReaction(t, user1, issue, nil, "heart")
 	addReaction(t, user2, issue, nil, "heart")
@@ -92,7 +93,7 @@ func TestIssueReactionCount(t *testing.T) {
 	addReaction(t, user4, issue, nil, "heart")
 	addReaction(t, ghost, issue, nil, "-1")
 
-	err := issue.loadReactions(x)
+	err := issue.loadReactions(db.DefaultContext().Engine())
 	assert.NoError(t, err)
 
 	assert.Len(t, issue.Reactions, 7)
@@ -110,31 +111,31 @@ func TestIssueReactionCount(t *testing.T) {
 }
 
 func TestIssueCommentAddReaction(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user1 := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	user1 := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 
-	issue1 := AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
+	issue1 := db.AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
 
-	comment1 := AssertExistsAndLoadBean(t, &Comment{ID: 1}).(*Comment)
+	comment1 := db.AssertExistsAndLoadBean(t, &Comment{ID: 1}).(*Comment)
 
 	addReaction(t, user1, issue1, comment1, "heart")
 
-	AssertExistsAndLoadBean(t, &Reaction{Type: "heart", UserID: user1.ID, IssueID: issue1.ID, CommentID: comment1.ID})
+	db.AssertExistsAndLoadBean(t, &Reaction{Type: "heart", UserID: user1.ID, IssueID: issue1.ID, CommentID: comment1.ID})
 }
 
 func TestIssueCommentDeleteReaction(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user1 := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
-	user2 := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
-	user3 := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
-	user4 := AssertExistsAndLoadBean(t, &User{ID: 4}).(*User)
+	user1 := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	user2 := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user3 := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	user4 := db.AssertExistsAndLoadBean(t, &User{ID: 4}).(*User)
 
-	issue1 := AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
-	repo1 := AssertExistsAndLoadBean(t, &Repository{ID: issue1.RepoID}).(*Repository)
+	issue1 := db.AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
+	repo1 := db.AssertExistsAndLoadBean(t, &Repository{ID: issue1.RepoID}).(*Repository)
 
-	comment1 := AssertExistsAndLoadBean(t, &Comment{ID: 1}).(*Comment)
+	comment1 := db.AssertExistsAndLoadBean(t, &Comment{ID: 1}).(*Comment)
 
 	addReaction(t, user1, issue1, comment1, "heart")
 	addReaction(t, user2, issue1, comment1, "heart")
@@ -151,16 +152,16 @@ func TestIssueCommentDeleteReaction(t *testing.T) {
 }
 
 func TestIssueCommentReactionCount(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user1 := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	user1 := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 
-	issue1 := AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
+	issue1 := db.AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
 
-	comment1 := AssertExistsAndLoadBean(t, &Comment{ID: 1}).(*Comment)
+	comment1 := db.AssertExistsAndLoadBean(t, &Comment{ID: 1}).(*Comment)
 
 	addReaction(t, user1, issue1, comment1, "heart")
 	assert.NoError(t, DeleteCommentReaction(user1, issue1, comment1, "heart"))
 
-	AssertNotExistsBean(t, &Reaction{Type: "heart", UserID: user1.ID, IssueID: issue1.ID, CommentID: comment1.ID})
+	db.AssertNotExistsBean(t, &Reaction{Type: "heart", UserID: user1.ID, IssueID: issue1.ID, CommentID: comment1.ID})
 }
diff --git a/models/issue_stopwatch.go b/models/issue_stopwatch.go
index b3022cfc2..1e8cf4c6a 100644
--- a/models/issue_stopwatch.go
+++ b/models/issue_stopwatch.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/timeutil"
 
 	"xorm.io/xorm"
@@ -21,6 +22,10 @@ type Stopwatch struct {
 	CreatedUnix timeutil.TimeStamp `xorm:"created"`
 }
 
+func init() {
+	db.RegisterModel(new(Stopwatch))
+}
+
 // Seconds returns the amount of time passed since creation, based on local server time
 func (s Stopwatch) Seconds() int64 {
 	return int64(timeutil.TimeStampNow() - s.CreatedUnix)
@@ -31,7 +36,7 @@ func (s Stopwatch) Duration() string {
 	return SecToTime(s.Seconds())
 }
 
-func getStopwatch(e Engine, userID, issueID int64) (sw *Stopwatch, exists bool, err error) {
+func getStopwatch(e db.Engine, userID, issueID int64) (sw *Stopwatch, exists bool, err error) {
 	sw = new(Stopwatch)
 	exists, err = e.
 		Where("user_id = ?", userID).
@@ -43,7 +48,7 @@ func getStopwatch(e Engine, userID, issueID int64) (sw *Stopwatch, exists bool,
 // GetUserStopwatches return list of all stopwatches of a user
 func GetUserStopwatches(userID int64, listOptions ListOptions) ([]*Stopwatch, error) {
 	sws := make([]*Stopwatch, 0, 8)
-	sess := x.Where("stopwatch.user_id = ?", userID)
+	sess := db.DefaultContext().Engine().Where("stopwatch.user_id = ?", userID)
 	if listOptions.Page != 0 {
 		sess = setSessionPagination(sess, &listOptions)
 	}
@@ -57,21 +62,21 @@ func GetUserStopwatches(userID int64, listOptions ListOptions) ([]*Stopwatch, er
 
 // CountUserStopwatches return count of all stopwatches of a user
 func CountUserStopwatches(userID int64) (int64, error) {
-	return x.Where("user_id = ?", userID).Count(&Stopwatch{})
+	return db.DefaultContext().Engine().Where("user_id = ?", userID).Count(&Stopwatch{})
 }
 
 // StopwatchExists returns true if the stopwatch exists
 func StopwatchExists(userID, issueID int64) bool {
-	_, exists, _ := getStopwatch(x, userID, issueID)
+	_, exists, _ := getStopwatch(db.DefaultContext().Engine(), userID, issueID)
 	return exists
 }
 
 // HasUserStopwatch returns true if the user has a stopwatch
 func HasUserStopwatch(userID int64) (exists bool, sw *Stopwatch, err error) {
-	return hasUserStopwatch(x, userID)
+	return hasUserStopwatch(db.DefaultContext().Engine(), userID)
 }
 
-func hasUserStopwatch(e Engine, userID int64) (exists bool, sw *Stopwatch, err error) {
+func hasUserStopwatch(e db.Engine, userID int64) (exists bool, sw *Stopwatch, err error) {
 	sw = new(Stopwatch)
 	exists, err = e.
 		Where("user_id = ?", userID).
@@ -81,7 +86,7 @@ func hasUserStopwatch(e Engine, userID int64) (exists bool, sw *Stopwatch, err e
 
 // CreateOrStopIssueStopwatch will create or remove a stopwatch and will log it into issue's timeline.
 func CreateOrStopIssueStopwatch(user *User, issue *Issue) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -170,7 +175,7 @@ func createOrStopIssueStopwatch(e *xorm.Session, user *User, issue *Issue) error
 
 // CancelStopwatch removes the given stopwatch and logs it into issue's timeline.
 func CancelStopwatch(user *User, issue *Issue) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
diff --git a/models/issue_stopwatch_test.go b/models/issue_stopwatch_test.go
index b6af5e93b..11306efcf 100644
--- a/models/issue_stopwatch_test.go
+++ b/models/issue_stopwatch_test.go
@@ -7,13 +7,14 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/timeutil"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestCancelStopwatch(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	user1, err := GetUserByID(1)
 	assert.NoError(t, err)
@@ -25,22 +26,22 @@ func TestCancelStopwatch(t *testing.T) {
 
 	err = CancelStopwatch(user1, issue1)
 	assert.NoError(t, err)
-	AssertNotExistsBean(t, &Stopwatch{UserID: user1.ID, IssueID: issue1.ID})
+	db.AssertNotExistsBean(t, &Stopwatch{UserID: user1.ID, IssueID: issue1.ID})
 
-	_ = AssertExistsAndLoadBean(t, &Comment{Type: CommentTypeCancelTracking, PosterID: user1.ID, IssueID: issue1.ID})
+	_ = db.AssertExistsAndLoadBean(t, &Comment{Type: CommentTypeCancelTracking, PosterID: user1.ID, IssueID: issue1.ID})
 
 	assert.Nil(t, CancelStopwatch(user1, issue2))
 }
 
 func TestStopwatchExists(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	assert.True(t, StopwatchExists(1, 1))
 	assert.False(t, StopwatchExists(1, 2))
 }
 
 func TestHasUserStopwatch(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	exists, sw, err := HasUserStopwatch(1)
 	assert.NoError(t, err)
@@ -53,7 +54,7 @@ func TestHasUserStopwatch(t *testing.T) {
 }
 
 func TestCreateOrStopIssueStopwatch(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	user2, err := GetUserByID(2)
 	assert.NoError(t, err)
@@ -66,10 +67,10 @@ func TestCreateOrStopIssueStopwatch(t *testing.T) {
 	assert.NoError(t, err)
 
 	assert.NoError(t, CreateOrStopIssueStopwatch(user3, issue1))
-	sw := AssertExistsAndLoadBean(t, &Stopwatch{UserID: 3, IssueID: 1}).(*Stopwatch)
+	sw := db.AssertExistsAndLoadBean(t, &Stopwatch{UserID: 3, IssueID: 1}).(*Stopwatch)
 	assert.LessOrEqual(t, sw.CreatedUnix, timeutil.TimeStampNow())
 
 	assert.NoError(t, CreateOrStopIssueStopwatch(user2, issue2))
-	AssertNotExistsBean(t, &Stopwatch{UserID: 2, IssueID: 2})
-	AssertExistsAndLoadBean(t, &TrackedTime{UserID: 2, IssueID: 2})
+	db.AssertNotExistsBean(t, &Stopwatch{UserID: 2, IssueID: 2})
+	db.AssertExistsAndLoadBean(t, &TrackedTime{UserID: 2, IssueID: 2})
 }
diff --git a/models/issue_test.go b/models/issue_test.go
index f2c9b7a68..a0ced7755 100644
--- a/models/issue_test.go
+++ b/models/issue_test.go
@@ -5,29 +5,32 @@
 package models
 
 import (
+	"fmt"
 	"sort"
+	"sync"
 	"testing"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestIssue_ReplaceLabels(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	testSuccess := func(issueID int64, labelIDs []int64) {
-		issue := AssertExistsAndLoadBean(t, &Issue{ID: issueID}).(*Issue)
-		repo := AssertExistsAndLoadBean(t, &Repository{ID: issue.RepoID}).(*Repository)
-		doer := AssertExistsAndLoadBean(t, &User{ID: repo.OwnerID}).(*User)
+		issue := db.AssertExistsAndLoadBean(t, &Issue{ID: issueID}).(*Issue)
+		repo := db.AssertExistsAndLoadBean(t, &Repository{ID: issue.RepoID}).(*Repository)
+		doer := db.AssertExistsAndLoadBean(t, &User{ID: repo.OwnerID}).(*User)
 
 		labels := make([]*Label, len(labelIDs))
 		for i, labelID := range labelIDs {
-			labels[i] = AssertExistsAndLoadBean(t, &Label{ID: labelID, RepoID: repo.ID}).(*Label)
+			labels[i] = db.AssertExistsAndLoadBean(t, &Label{ID: labelID, RepoID: repo.ID}).(*Label)
 		}
 		assert.NoError(t, issue.ReplaceLabels(labels, doer))
-		AssertCount(t, &IssueLabel{IssueID: issueID}, len(labelIDs))
+		db.AssertCount(t, &IssueLabel{IssueID: issueID}, len(labelIDs))
 		for _, labelID := range labelIDs {
-			AssertExistsAndLoadBean(t, &IssueLabel{IssueID: issueID, LabelID: labelID})
+			db.AssertExistsAndLoadBean(t, &IssueLabel{IssueID: issueID, LabelID: labelID})
 		}
 	}
 
@@ -37,7 +40,7 @@ func TestIssue_ReplaceLabels(t *testing.T) {
 }
 
 func Test_GetIssueIDsByRepoID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	ids, err := GetIssueIDsByRepoID(1)
 	assert.NoError(t, err)
@@ -45,8 +48,8 @@ func Test_GetIssueIDsByRepoID(t *testing.T) {
 }
 
 func TestIssueAPIURL(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	issue := AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
+	assert.NoError(t, db.PrepareTestDatabase())
+	issue := db.AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
 	err := issue.LoadAttributes()
 
 	assert.NoError(t, err)
@@ -54,7 +57,7 @@ func TestIssueAPIURL(t *testing.T) {
 }
 
 func TestGetIssuesByIDs(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	testSuccess := func(expectedIssueIDs, nonExistentIssueIDs []int64) {
 		issues, err := GetIssuesByIDs(append(expectedIssueIDs, nonExistentIssueIDs...))
 		assert.NoError(t, err)
@@ -65,16 +68,16 @@ func TestGetIssuesByIDs(t *testing.T) {
 		assert.Equal(t, expectedIssueIDs, actualIssueIDs)
 	}
 	testSuccess([]int64{1, 2, 3}, []int64{})
-	testSuccess([]int64{1, 2, 3}, []int64{NonexistentID})
+	testSuccess([]int64{1, 2, 3}, []int64{db.NonexistentID})
 }
 
 func TestGetParticipantIDsByIssue(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	checkParticipants := func(issueID int64, userIDs []int) {
 		issue, err := GetIssueByID(issueID)
 		assert.NoError(t, err)
-		participants, err := issue.getParticipantIDsByIssue(x)
+		participants, err := issue.getParticipantIDsByIssue(db.DefaultContext().Engine())
 		if assert.NoError(t, err) {
 			participantsIDs := make([]int, len(participants))
 			for i, uid := range participants {
@@ -103,17 +106,17 @@ func TestIssue_ClearLabels(t *testing.T) {
 		{3, 2}, // pull-request, has no labels
 	}
 	for _, test := range tests {
-		assert.NoError(t, PrepareTestDatabase())
-		issue := AssertExistsAndLoadBean(t, &Issue{ID: test.issueID}).(*Issue)
-		doer := AssertExistsAndLoadBean(t, &User{ID: test.doerID}).(*User)
+		assert.NoError(t, db.PrepareTestDatabase())
+		issue := db.AssertExistsAndLoadBean(t, &Issue{ID: test.issueID}).(*Issue)
+		doer := db.AssertExistsAndLoadBean(t, &User{ID: test.doerID}).(*User)
 		assert.NoError(t, issue.ClearLabels(doer))
-		AssertNotExistsBean(t, &IssueLabel{IssueID: test.issueID})
+		db.AssertNotExistsBean(t, &IssueLabel{IssueID: test.issueID})
 	}
 }
 
 func TestUpdateIssueCols(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	issue := AssertExistsAndLoadBean(t, &Issue{}).(*Issue)
+	assert.NoError(t, db.PrepareTestDatabase())
+	issue := db.AssertExistsAndLoadBean(t, &Issue{}).(*Issue)
 
 	const newTitle = "New Title for unit test"
 	issue.Title = newTitle
@@ -122,17 +125,17 @@ func TestUpdateIssueCols(t *testing.T) {
 	issue.Content = "This should have no effect"
 
 	now := time.Now().Unix()
-	assert.NoError(t, updateIssueCols(x, issue, "name"))
+	assert.NoError(t, updateIssueCols(db.DefaultContext().Engine(), issue, "name"))
 	then := time.Now().Unix()
 
-	updatedIssue := AssertExistsAndLoadBean(t, &Issue{ID: issue.ID}).(*Issue)
+	updatedIssue := db.AssertExistsAndLoadBean(t, &Issue{ID: issue.ID}).(*Issue)
 	assert.EqualValues(t, newTitle, updatedIssue.Title)
 	assert.EqualValues(t, prevContent, updatedIssue.Content)
-	AssertInt64InRange(t, now, then, int64(updatedIssue.UpdatedUnix))
+	db.AssertInt64InRange(t, now, then, int64(updatedIssue.UpdatedUnix))
 }
 
 func TestIssues(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	for _, test := range []struct {
 		Opts             IssuesOptions
 		ExpectedIssueIDs []int64
@@ -187,7 +190,7 @@ func TestIssues(t *testing.T) {
 }
 
 func TestGetUserIssueStats(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	for _, test := range []struct {
 		Opts               UserIssueStatsOptions
 		ExpectedIssueStats IssueStats
@@ -284,15 +287,15 @@ func TestGetUserIssueStats(t *testing.T) {
 }
 
 func TestIssue_loadTotalTimes(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	ms, err := GetIssueByID(2)
 	assert.NoError(t, err)
-	assert.NoError(t, ms.loadTotalTimes(x))
+	assert.NoError(t, ms.loadTotalTimes(db.DefaultContext().Engine()))
 	assert.Equal(t, int64(3682), ms.TotalTrackedTime)
 }
 
 func TestIssue_SearchIssueIDsByKeyword(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	total, ids, err := SearchIssueIDsByKeyword("issue2", []int64{1}, 10, 0)
 	assert.NoError(t, err)
 	assert.EqualValues(t, 1, total)
@@ -316,8 +319,8 @@ func TestIssue_SearchIssueIDsByKeyword(t *testing.T) {
 }
 
 func TestGetRepoIDsForIssuesOptions(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	user := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	for _, test := range []struct {
 		Opts            IssuesOptions
 		ExpectedRepoIDs []int64
@@ -348,8 +351,8 @@ func TestGetRepoIDsForIssuesOptions(t *testing.T) {
 func testInsertIssue(t *testing.T, title, content string, expectIndex int64) *Issue {
 	var newIssue Issue
 	t.Run(title, func(t *testing.T) {
-		repo := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
-		user := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+		repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+		user := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 
 		issue := Issue{
 			RepoID:   repo.ID,
@@ -360,7 +363,7 @@ func testInsertIssue(t *testing.T, title, content string, expectIndex int64) *Is
 		err := NewIssue(repo, &issue, nil, nil)
 		assert.NoError(t, err)
 
-		has, err := x.ID(issue.ID).Get(&newIssue)
+		has, err := db.DefaultContext().Engine().ID(issue.ID).Get(&newIssue)
 		assert.NoError(t, err)
 		assert.True(t, has)
 		assert.EqualValues(t, issue.Title, newIssue.Title)
@@ -373,28 +376,28 @@ func testInsertIssue(t *testing.T, title, content string, expectIndex int64) *Is
 }
 
 func TestIssue_InsertIssue(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// there are 5 issues and max index is 5 on repository 1, so this one should 6
 	issue := testInsertIssue(t, "my issue1", "special issue's comments?", 6)
-	_, err := x.ID(issue.ID).Delete(new(Issue))
+	_, err := db.DefaultContext().Engine().ID(issue.ID).Delete(new(Issue))
 	assert.NoError(t, err)
 
 	issue = testInsertIssue(t, `my issue2, this is my son's love \n \r \ `, "special issue's '' comments?", 7)
-	_, err = x.ID(issue.ID).Delete(new(Issue))
+	_, err = db.DefaultContext().Engine().ID(issue.ID).Delete(new(Issue))
 	assert.NoError(t, err)
 
 }
 
 func TestIssue_ResolveMentions(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	testSuccess := func(owner, repo, doer string, mentions []string, expected []int64) {
-		o := AssertExistsAndLoadBean(t, &User{LowerName: owner}).(*User)
-		r := AssertExistsAndLoadBean(t, &Repository{OwnerID: o.ID, LowerName: repo}).(*Repository)
+		o := db.AssertExistsAndLoadBean(t, &User{LowerName: owner}).(*User)
+		r := db.AssertExistsAndLoadBean(t, &Repository{OwnerID: o.ID, LowerName: repo}).(*Repository)
 		issue := &Issue{RepoID: r.ID}
-		d := AssertExistsAndLoadBean(t, &User{LowerName: doer}).(*User)
-		resolved, err := issue.ResolveMentionsByVisibility(DefaultDBContext(), d, mentions)
+		d := db.AssertExistsAndLoadBean(t, &User{LowerName: doer}).(*User)
+		resolved, err := issue.ResolveMentionsByVisibility(db.DefaultContext(), d, mentions)
 		assert.NoError(t, err)
 		ids := make([]int64, len(resolved))
 		for i, user := range resolved {
@@ -417,3 +420,17 @@ func TestIssue_ResolveMentions(t *testing.T) {
 	// Private repo, whole team
 	testSuccess("user17", "big_test_private_4", "user15", []string{"user17/owners"}, []int64{18})
 }
+
+func TestResourceIndex(t *testing.T) {
+	assert.NoError(t, db.PrepareTestDatabase())
+
+	var wg sync.WaitGroup
+	for i := 0; i < 100; i++ {
+		wg.Add(1)
+		go func(i int) {
+			testInsertIssue(t, fmt.Sprintf("issue %d", i+1), "my issue", 0)
+			wg.Done()
+		}(i)
+	}
+	wg.Wait()
+}
diff --git a/models/issue_tracked_time.go b/models/issue_tracked_time.go
index 09db45bf9..77b44df1e 100644
--- a/models/issue_tracked_time.go
+++ b/models/issue_tracked_time.go
@@ -7,6 +7,7 @@ package models
 import (
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 
 	"xorm.io/builder"
@@ -25,6 +26,10 @@ type TrackedTime struct {
 	Deleted     bool      `xorm:"NOT NULL DEFAULT false"`
 }
 
+func init() {
+	db.RegisterModel(new(TrackedTime))
+}
+
 // TrackedTimeList is a List of TrackedTime's
 type TrackedTimeList []*TrackedTime
 
@@ -35,10 +40,10 @@ func (t *TrackedTime) AfterLoad() {
 
 // LoadAttributes load Issue, User
 func (t *TrackedTime) LoadAttributes() (err error) {
-	return t.loadAttributes(x)
+	return t.loadAttributes(db.DefaultContext().Engine())
 }
 
-func (t *TrackedTime) loadAttributes(e Engine) (err error) {
+func (t *TrackedTime) loadAttributes(e db.Engine) (err error) {
 	if t.Issue == nil {
 		t.Issue, err = getIssueByID(e, t.IssueID)
 		if err != nil {
@@ -104,7 +109,7 @@ func (opts *FindTrackedTimesOptions) toCond() builder.Cond {
 }
 
 // toSession will convert the given options to a xorm Session by using the conditions from toCond and joining with issue table if required
-func (opts *FindTrackedTimesOptions) toSession(e Engine) Engine {
+func (opts *FindTrackedTimesOptions) toSession(e db.Engine) db.Engine {
 	sess := e
 	if opts.RepositoryID > 0 || opts.MilestoneID > 0 {
 		sess = e.Join("INNER", "issue", "issue.id = tracked_time.issue_id")
@@ -119,37 +124,37 @@ func (opts *FindTrackedTimesOptions) toSession(e Engine) Engine {
 	return sess
 }
 
-func getTrackedTimes(e Engine, options *FindTrackedTimesOptions) (trackedTimes TrackedTimeList, err error) {
+func getTrackedTimes(e db.Engine, options *FindTrackedTimesOptions) (trackedTimes TrackedTimeList, err error) {
 	err = options.toSession(e).Find(&trackedTimes)
 	return
 }
 
 // GetTrackedTimes returns all tracked times that fit to the given options.
 func GetTrackedTimes(opts *FindTrackedTimesOptions) (TrackedTimeList, error) {
-	return getTrackedTimes(x, opts)
+	return getTrackedTimes(db.DefaultContext().Engine(), opts)
 }
 
 // CountTrackedTimes returns count of tracked times that fit to the given options.
 func CountTrackedTimes(opts *FindTrackedTimesOptions) (int64, error) {
-	sess := x.Where(opts.toCond())
+	sess := db.DefaultContext().Engine().Where(opts.toCond())
 	if opts.RepositoryID > 0 || opts.MilestoneID > 0 {
 		sess = sess.Join("INNER", "issue", "issue.id = tracked_time.issue_id")
 	}
 	return sess.Count(&TrackedTime{})
 }
 
-func getTrackedSeconds(e Engine, opts FindTrackedTimesOptions) (trackedSeconds int64, err error) {
+func getTrackedSeconds(e db.Engine, opts FindTrackedTimesOptions) (trackedSeconds int64, err error) {
 	return opts.toSession(e).SumInt(&TrackedTime{}, "time")
 }
 
 // GetTrackedSeconds return sum of seconds
 func GetTrackedSeconds(opts FindTrackedTimesOptions) (int64, error) {
-	return getTrackedSeconds(x, opts)
+	return getTrackedSeconds(db.DefaultContext().Engine(), opts)
 }
 
 // AddTime will add the given time (in seconds) to the issue
 func AddTime(user *User, issue *Issue, amount int64, created time.Time) (*TrackedTime, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	if err := sess.Begin(); err != nil {
@@ -179,7 +184,7 @@ func AddTime(user *User, issue *Issue, amount int64, created time.Time) (*Tracke
 	return t, sess.Commit()
 }
 
-func addTime(e Engine, user *User, issue *Issue, amount int64, created time.Time) (*TrackedTime, error) {
+func addTime(e db.Engine, user *User, issue *Issue, amount int64, created time.Time) (*TrackedTime, error) {
 	if created.IsZero() {
 		created = time.Now()
 	}
@@ -225,7 +230,7 @@ func TotalTimes(options *FindTrackedTimesOptions) (map[*User]string, error) {
 
 // DeleteIssueUserTimes deletes times for issue
 func DeleteIssueUserTimes(issue *Issue, user *User) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	if err := sess.Begin(); err != nil {
@@ -263,7 +268,7 @@ func DeleteIssueUserTimes(issue *Issue, user *User) error {
 
 // DeleteTime delete a specific Time
 func DeleteTime(t *TrackedTime) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	if err := sess.Begin(); err != nil {
@@ -291,7 +296,7 @@ func DeleteTime(t *TrackedTime) error {
 	return sess.Commit()
 }
 
-func deleteTimes(e Engine, opts FindTrackedTimesOptions) (removedTime int64, err error) {
+func deleteTimes(e db.Engine, opts FindTrackedTimesOptions) (removedTime int64, err error) {
 	removedTime, err = getTrackedSeconds(e, opts)
 	if err != nil || removedTime == 0 {
 		return
@@ -301,7 +306,7 @@ func deleteTimes(e Engine, opts FindTrackedTimesOptions) (removedTime int64, err
 	return
 }
 
-func deleteTime(e Engine, t *TrackedTime) error {
+func deleteTime(e db.Engine, t *TrackedTime) error {
 	if t.Deleted {
 		return ErrNotExist{ID: t.ID}
 	}
@@ -313,7 +318,7 @@ func deleteTime(e Engine, t *TrackedTime) error {
 // GetTrackedTimeByID returns raw TrackedTime without loading attributes by id
 func GetTrackedTimeByID(id int64) (*TrackedTime, error) {
 	time := new(TrackedTime)
-	has, err := x.ID(id).Get(time)
+	has, err := db.DefaultContext().Engine().ID(id).Get(time)
 	if err != nil {
 		return nil, err
 	} else if !has {
diff --git a/models/issue_tracked_time_test.go b/models/issue_tracked_time_test.go
index 9de1dd699..764336072 100644
--- a/models/issue_tracked_time_test.go
+++ b/models/issue_tracked_time_test.go
@@ -8,11 +8,12 @@ import (
 	"testing"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestAddTime(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	user3, err := GetUserByID(3)
 	assert.NoError(t, err)
@@ -27,15 +28,15 @@ func TestAddTime(t *testing.T) {
 	assert.Equal(t, int64(1), trackedTime.IssueID)
 	assert.Equal(t, int64(3661), trackedTime.Time)
 
-	tt := AssertExistsAndLoadBean(t, &TrackedTime{UserID: 3, IssueID: 1}).(*TrackedTime)
+	tt := db.AssertExistsAndLoadBean(t, &TrackedTime{UserID: 3, IssueID: 1}).(*TrackedTime)
 	assert.Equal(t, int64(3661), tt.Time)
 
-	comment := AssertExistsAndLoadBean(t, &Comment{Type: CommentTypeAddTimeManual, PosterID: 3, IssueID: 1}).(*Comment)
+	comment := db.AssertExistsAndLoadBean(t, &Comment{Type: CommentTypeAddTimeManual, PosterID: 3, IssueID: 1}).(*Comment)
 	assert.Equal(t, comment.Content, "1h 1min 1s")
 }
 
 func TestGetTrackedTimes(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// by Issue
 	times, err := GetTrackedTimes(&FindTrackedTimesOptions{IssueID: 1})
@@ -76,7 +77,7 @@ func TestGetTrackedTimes(t *testing.T) {
 }
 
 func TestTotalTimes(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	total, err := TotalTimes(&FindTrackedTimesOptions{IssueID: 1})
 	assert.NoError(t, err)
diff --git a/models/issue_user.go b/models/issue_user.go
index 67a118fe5..6f9b7591c 100644
--- a/models/issue_user.go
+++ b/models/issue_user.go
@@ -6,6 +6,8 @@ package models
 
 import (
 	"fmt"
+
+	"code.gitea.io/gitea/models/db"
 )
 
 // IssueUser represents an issue-user relation.
@@ -17,7 +19,11 @@ type IssueUser struct {
 	IsMentioned bool
 }
 
-func newIssueUsers(e Engine, repo *Repository, issue *Issue) error {
+func init() {
+	db.RegisterModel(new(IssueUser))
+}
+
+func newIssueUsers(e db.Engine, repo *Repository, issue *Issue) error {
 	assignees, err := repo.getAssignees(e)
 	if err != nil {
 		return fmt.Errorf("getAssignees: %v", err)
@@ -51,27 +57,27 @@ func newIssueUsers(e Engine, repo *Repository, issue *Issue) error {
 
 // UpdateIssueUserByRead updates issue-user relation for reading.
 func UpdateIssueUserByRead(uid, issueID int64) error {
-	_, err := x.Exec("UPDATE `issue_user` SET is_read=? WHERE uid=? AND issue_id=?", true, uid, issueID)
+	_, err := db.DefaultContext().Engine().Exec("UPDATE `issue_user` SET is_read=? WHERE uid=? AND issue_id=?", true, uid, issueID)
 	return err
 }
 
 // UpdateIssueUsersByMentions updates issue-user pairs by mentioning.
-func UpdateIssueUsersByMentions(ctx DBContext, issueID int64, uids []int64) error {
+func UpdateIssueUsersByMentions(ctx *db.Context, issueID int64, uids []int64) error {
 	for _, uid := range uids {
 		iu := &IssueUser{
 			UID:     uid,
 			IssueID: issueID,
 		}
-		has, err := ctx.e.Get(iu)
+		has, err := ctx.Engine().Get(iu)
 		if err != nil {
 			return err
 		}
 
 		iu.IsMentioned = true
 		if has {
-			_, err = ctx.e.ID(iu.ID).Cols("is_mentioned").Update(iu)
+			_, err = ctx.Engine().ID(iu.ID).Cols("is_mentioned").Update(iu)
 		} else {
-			_, err = ctx.e.Insert(iu)
+			_, err = ctx.Engine().Insert(iu)
 		}
 		if err != nil {
 			return err
diff --git a/models/issue_user_test.go b/models/issue_user_test.go
index 01e0bdc64..ca45d0656 100644
--- a/models/issue_user_test.go
+++ b/models/issue_user_test.go
@@ -7,13 +7,14 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func Test_newIssueUsers(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
 	newIssue := &Issue{
 		RepoID:   repo.ID,
 		PosterID: 4,
@@ -23,35 +24,35 @@ func Test_newIssueUsers(t *testing.T) {
 	}
 
 	// artificially insert new issue
-	AssertSuccessfulInsert(t, newIssue)
+	db.AssertSuccessfulInsert(t, newIssue)
 
-	assert.NoError(t, newIssueUsers(x, repo, newIssue))
+	assert.NoError(t, newIssueUsers(db.DefaultContext().Engine(), repo, newIssue))
 
 	// issue_user table should now have entries for new issue
-	AssertExistsAndLoadBean(t, &IssueUser{IssueID: newIssue.ID, UID: newIssue.PosterID})
-	AssertExistsAndLoadBean(t, &IssueUser{IssueID: newIssue.ID, UID: repo.OwnerID})
+	db.AssertExistsAndLoadBean(t, &IssueUser{IssueID: newIssue.ID, UID: newIssue.PosterID})
+	db.AssertExistsAndLoadBean(t, &IssueUser{IssueID: newIssue.ID, UID: repo.OwnerID})
 }
 
 func TestUpdateIssueUserByRead(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	issue := AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
+	assert.NoError(t, db.PrepareTestDatabase())
+	issue := db.AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
 
 	assert.NoError(t, UpdateIssueUserByRead(4, issue.ID))
-	AssertExistsAndLoadBean(t, &IssueUser{IssueID: issue.ID, UID: 4}, "is_read=1")
+	db.AssertExistsAndLoadBean(t, &IssueUser{IssueID: issue.ID, UID: 4}, "is_read=1")
 
 	assert.NoError(t, UpdateIssueUserByRead(4, issue.ID))
-	AssertExistsAndLoadBean(t, &IssueUser{IssueID: issue.ID, UID: 4}, "is_read=1")
+	db.AssertExistsAndLoadBean(t, &IssueUser{IssueID: issue.ID, UID: 4}, "is_read=1")
 
-	assert.NoError(t, UpdateIssueUserByRead(NonexistentID, NonexistentID))
+	assert.NoError(t, UpdateIssueUserByRead(db.NonexistentID, db.NonexistentID))
 }
 
 func TestUpdateIssueUsersByMentions(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	issue := AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
+	assert.NoError(t, db.PrepareTestDatabase())
+	issue := db.AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
 
 	uids := []int64{2, 5}
-	assert.NoError(t, UpdateIssueUsersByMentions(DefaultDBContext(), issue.ID, uids))
+	assert.NoError(t, UpdateIssueUsersByMentions(db.DefaultContext(), issue.ID, uids))
 	for _, uid := range uids {
-		AssertExistsAndLoadBean(t, &IssueUser{IssueID: issue.ID, UID: uid}, "is_mentioned=1")
+		db.AssertExistsAndLoadBean(t, &IssueUser{IssueID: issue.ID, UID: uid}, "is_mentioned=1")
 	}
 }
diff --git a/models/issue_watch.go b/models/issue_watch.go
index 56811e508..dd693f82f 100644
--- a/models/issue_watch.go
+++ b/models/issue_watch.go
@@ -5,6 +5,7 @@
 package models
 
 import (
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/timeutil"
 )
 
@@ -18,12 +19,16 @@ type IssueWatch struct {
 	UpdatedUnix timeutil.TimeStamp `xorm:"updated NOT NULL"`
 }
 
+func init() {
+	db.RegisterModel(new(IssueWatch))
+}
+
 // IssueWatchList contains IssueWatch
 type IssueWatchList []*IssueWatch
 
 // CreateOrUpdateIssueWatch set watching for a user and issue
 func CreateOrUpdateIssueWatch(userID, issueID int64, isWatching bool) error {
-	iw, exists, err := getIssueWatch(x, userID, issueID)
+	iw, exists, err := getIssueWatch(db.DefaultContext().Engine(), userID, issueID)
 	if err != nil {
 		return err
 	}
@@ -35,13 +40,13 @@ func CreateOrUpdateIssueWatch(userID, issueID int64, isWatching bool) error {
 			IsWatching: isWatching,
 		}
 
-		if _, err := x.Insert(iw); err != nil {
+		if _, err := db.DefaultContext().Engine().Insert(iw); err != nil {
 			return err
 		}
 	} else {
 		iw.IsWatching = isWatching
 
-		if _, err := x.ID(iw.ID).Cols("is_watching", "updated_unix").Update(iw); err != nil {
+		if _, err := db.DefaultContext().Engine().ID(iw.ID).Cols("is_watching", "updated_unix").Update(iw); err != nil {
 			return err
 		}
 	}
@@ -51,11 +56,11 @@ func CreateOrUpdateIssueWatch(userID, issueID int64, isWatching bool) error {
 // GetIssueWatch returns all IssueWatch objects from db by user and issue
 // the current Web-UI need iw object for watchers AND explicit non-watchers
 func GetIssueWatch(userID, issueID int64) (iw *IssueWatch, exists bool, err error) {
-	return getIssueWatch(x, userID, issueID)
+	return getIssueWatch(db.DefaultContext().Engine(), userID, issueID)
 }
 
 // Return watcher AND explicit non-watcher if entry in db exist
-func getIssueWatch(e Engine, userID, issueID int64) (iw *IssueWatch, exists bool, err error) {
+func getIssueWatch(e db.Engine, userID, issueID int64) (iw *IssueWatch, exists bool, err error) {
 	iw = new(IssueWatch)
 	exists, err = e.
 		Where("user_id = ?", userID).
@@ -67,14 +72,14 @@ func getIssueWatch(e Engine, userID, issueID int64) (iw *IssueWatch, exists bool
 // CheckIssueWatch check if an user is watching an issue
 // it takes participants and repo watch into account
 func CheckIssueWatch(user *User, issue *Issue) (bool, error) {
-	iw, exist, err := getIssueWatch(x, user.ID, issue.ID)
+	iw, exist, err := getIssueWatch(db.DefaultContext().Engine(), user.ID, issue.ID)
 	if err != nil {
 		return false, err
 	}
 	if exist {
 		return iw.IsWatching, nil
 	}
-	w, err := getWatch(x, user.ID, issue.RepoID)
+	w, err := getWatch(db.DefaultContext().Engine(), user.ID, issue.RepoID)
 	if err != nil {
 		return false, err
 	}
@@ -85,10 +90,10 @@ func CheckIssueWatch(user *User, issue *Issue) (bool, error) {
 // but avoids joining with `user` for performance reasons
 // User permissions must be verified elsewhere if required
 func GetIssueWatchersIDs(issueID int64, watching bool) ([]int64, error) {
-	return getIssueWatchersIDs(x, issueID, watching)
+	return getIssueWatchersIDs(db.DefaultContext().Engine(), issueID, watching)
 }
 
-func getIssueWatchersIDs(e Engine, issueID int64, watching bool) ([]int64, error) {
+func getIssueWatchersIDs(e db.Engine, issueID int64, watching bool) ([]int64, error) {
 	ids := make([]int64, 0, 64)
 	return ids, e.Table("issue_watch").
 		Where("issue_id=?", issueID).
@@ -99,10 +104,10 @@ func getIssueWatchersIDs(e Engine, issueID int64, watching bool) ([]int64, error
 
 // GetIssueWatchers returns watchers/unwatchers of a given issue
 func GetIssueWatchers(issueID int64, listOptions ListOptions) (IssueWatchList, error) {
-	return getIssueWatchers(x, issueID, listOptions)
+	return getIssueWatchers(db.DefaultContext().Engine(), issueID, listOptions)
 }
 
-func getIssueWatchers(e Engine, issueID int64, listOptions ListOptions) (IssueWatchList, error) {
+func getIssueWatchers(e db.Engine, issueID int64, listOptions ListOptions) (IssueWatchList, error) {
 	sess := e.
 		Where("`issue_watch`.issue_id = ?", issueID).
 		And("`issue_watch`.is_watching = ?", true).
@@ -119,7 +124,7 @@ func getIssueWatchers(e Engine, issueID int64, listOptions ListOptions) (IssueWa
 	return watches, sess.Find(&watches)
 }
 
-func removeIssueWatchersByRepoID(e Engine, userID, repoID int64) error {
+func removeIssueWatchersByRepoID(e db.Engine, userID, repoID int64) error {
 	_, err := e.
 		Join("INNER", "issue", "`issue`.id = `issue_watch`.issue_id AND `issue`.repo_id = ?", repoID).
 		Where("`issue_watch`.user_id = ?", userID).
diff --git a/models/issue_watch_test.go b/models/issue_watch_test.go
index 013ca67e1..f85e7cef5 100644
--- a/models/issue_watch_test.go
+++ b/models/issue_watch_test.go
@@ -7,23 +7,24 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestCreateOrUpdateIssueWatch(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	assert.NoError(t, CreateOrUpdateIssueWatch(3, 1, true))
-	iw := AssertExistsAndLoadBean(t, &IssueWatch{UserID: 3, IssueID: 1}).(*IssueWatch)
+	iw := db.AssertExistsAndLoadBean(t, &IssueWatch{UserID: 3, IssueID: 1}).(*IssueWatch)
 	assert.True(t, iw.IsWatching)
 
 	assert.NoError(t, CreateOrUpdateIssueWatch(1, 1, false))
-	iw = AssertExistsAndLoadBean(t, &IssueWatch{UserID: 1, IssueID: 1}).(*IssueWatch)
+	iw = db.AssertExistsAndLoadBean(t, &IssueWatch{UserID: 1, IssueID: 1}).(*IssueWatch)
 	assert.False(t, iw.IsWatching)
 }
 
 func TestGetIssueWatch(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	_, exists, err := GetIssueWatch(9, 1)
 	assert.True(t, exists)
@@ -40,7 +41,7 @@ func TestGetIssueWatch(t *testing.T) {
 }
 
 func TestGetIssueWatchers(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	iws, err := GetIssueWatchers(1, ListOptions{})
 	assert.NoError(t, err)
diff --git a/models/issue_xref.go b/models/issue_xref.go
index fc8dd70f7..3f9c1e7f5 100644
--- a/models/issue_xref.go
+++ b/models/issue_xref.go
@@ -7,10 +7,9 @@ package models
 import (
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/references"
-
-	"xorm.io/xorm"
 )
 
 type crossReference struct {
@@ -27,7 +26,7 @@ type crossReferencesContext struct {
 	RemoveOld   bool
 }
 
-func findOldCrossReferences(e Engine, issueID, commentID int64) ([]*Comment, error) {
+func findOldCrossReferences(e db.Engine, issueID, commentID int64) ([]*Comment, error) {
 	active := make([]*Comment, 0, 10)
 	return active, e.Where("`ref_action` IN (?, ?, ?)", references.XRefActionNone, references.XRefActionCloses, references.XRefActionReopens).
 		And("`ref_issue_id` = ?", issueID).
@@ -35,7 +34,7 @@ func findOldCrossReferences(e Engine, issueID, commentID int64) ([]*Comment, err
 		Find(&active)
 }
 
-func neuterCrossReferences(e Engine, issueID, commentID int64) error {
+func neuterCrossReferences(e db.Engine, issueID, commentID int64) error {
 	active, err := findOldCrossReferences(e, issueID, commentID)
 	if err != nil {
 		return err
@@ -47,7 +46,7 @@ func neuterCrossReferences(e Engine, issueID, commentID int64) error {
 	return neuterCrossReferencesIds(e, ids)
 }
 
-func neuterCrossReferencesIds(e Engine, ids []int64) error {
+func neuterCrossReferencesIds(e db.Engine, ids []int64) error {
 	_, err := e.In("id", ids).Cols("`ref_action`").Update(&Comment{RefAction: references.XRefActionNeutered})
 	return err
 }
@@ -60,7 +59,7 @@ func neuterCrossReferencesIds(e Engine, ids []int64) error {
 //          \/     \/            \/
 //
 
-func (issue *Issue) addCrossReferences(e *xorm.Session, doer *User, removeOld bool) error {
+func (issue *Issue) addCrossReferences(e db.Engine, doer *User, removeOld bool) error {
 	var commentType CommentType
 	if issue.IsPull {
 		commentType = CommentTypePullRef
@@ -76,7 +75,7 @@ func (issue *Issue) addCrossReferences(e *xorm.Session, doer *User, removeOld bo
 	return issue.createCrossReferences(e, ctx, issue.Title, issue.Content)
 }
 
-func (issue *Issue) createCrossReferences(e *xorm.Session, ctx *crossReferencesContext, plaincontent, mdcontent string) error {
+func (issue *Issue) createCrossReferences(e db.Engine, ctx *crossReferencesContext, plaincontent, mdcontent string) error {
 	xreflist, err := ctx.OrigIssue.getCrossReferences(e, ctx, plaincontent, mdcontent)
 	if err != nil {
 		return err
@@ -134,7 +133,7 @@ func (issue *Issue) createCrossReferences(e *xorm.Session, ctx *crossReferencesC
 	return nil
 }
 
-func (issue *Issue) getCrossReferences(e *xorm.Session, ctx *crossReferencesContext, plaincontent, mdcontent string) ([]*crossReference, error) {
+func (issue *Issue) getCrossReferences(e db.Engine, ctx *crossReferencesContext, plaincontent, mdcontent string) ([]*crossReference, error) {
 	xreflist := make([]*crossReference, 0, 5)
 	var (
 		refRepo   *Repository
@@ -192,7 +191,7 @@ func (issue *Issue) updateCrossReferenceList(list []*crossReference, xref *cross
 }
 
 // verifyReferencedIssue will check if the referenced issue exists, and whether the doer has permission to do what
-func (issue *Issue) verifyReferencedIssue(e Engine, ctx *crossReferencesContext, repo *Repository,
+func (issue *Issue) verifyReferencedIssue(e db.Engine, ctx *crossReferencesContext, repo *Repository,
 	ref references.IssueReference) (*Issue, references.XRefAction, error) {
 	refIssue := &Issue{RepoID: repo.ID, Index: ref.Index}
 	refAction := ref.Action
@@ -241,7 +240,7 @@ func (issue *Issue) verifyReferencedIssue(e Engine, ctx *crossReferencesContext,
 //         \/             \/      \/     \/     \/
 //
 
-func (comment *Comment) addCrossReferences(e *xorm.Session, doer *User, removeOld bool) error {
+func (comment *Comment) addCrossReferences(e db.Engine, doer *User, removeOld bool) error {
 	if comment.Type != CommentTypeCode && comment.Type != CommentTypeComment {
 		return nil
 	}
@@ -258,7 +257,7 @@ func (comment *Comment) addCrossReferences(e *xorm.Session, doer *User, removeOl
 	return comment.Issue.createCrossReferences(e, ctx, "", comment.Content)
 }
 
-func (comment *Comment) neuterCrossReferences(e Engine) error {
+func (comment *Comment) neuterCrossReferences(e db.Engine) error {
 	return neuterCrossReferences(e, comment.IssueID, comment.ID)
 }
 
@@ -278,7 +277,7 @@ func (comment *Comment) LoadRefIssue() (err error) {
 	}
 	comment.RefIssue, err = GetIssueByID(comment.RefIssueID)
 	if err == nil {
-		err = comment.RefIssue.loadRepo(x)
+		err = comment.RefIssue.loadRepo(db.DefaultContext().Engine())
 	}
 	return
 }
@@ -338,7 +337,7 @@ func (comment *Comment) RefIssueIdent() string {
 // ResolveCrossReferences will return the list of references to close/reopen by this PR
 func (pr *PullRequest) ResolveCrossReferences() ([]*Comment, error) {
 	unfiltered := make([]*Comment, 0, 5)
-	if err := x.
+	if err := db.DefaultContext().Engine().
 		Where("ref_repo_id = ? AND ref_issue_id = ?", pr.Issue.RepoID, pr.Issue.ID).
 		In("ref_action", []references.XRefAction{references.XRefActionCloses, references.XRefActionReopens}).
 		OrderBy("id").
diff --git a/models/issue_xref_test.go b/models/issue_xref_test.go
index a2d1a4b11..1ef9e347f 100644
--- a/models/issue_xref_test.go
+++ b/models/issue_xref_test.go
@@ -8,13 +8,14 @@ import (
 	"fmt"
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/references"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestXRef_AddCrossReferences(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// Issue #1 to test against
 	itarget := testCreateIssue(t, 1, 2, "title1", "content1", false)
@@ -22,7 +23,7 @@ func TestXRef_AddCrossReferences(t *testing.T) {
 	// PR to close issue #1
 	content := fmt.Sprintf("content2, closes #%d", itarget.Index)
 	pr := testCreateIssue(t, 1, 2, "title2", content, true)
-	ref := AssertExistsAndLoadBean(t, &Comment{IssueID: itarget.ID, RefIssueID: pr.ID, RefCommentID: 0}).(*Comment)
+	ref := db.AssertExistsAndLoadBean(t, &Comment{IssueID: itarget.ID, RefIssueID: pr.ID, RefCommentID: 0}).(*Comment)
 	assert.Equal(t, CommentTypePullRef, ref.Type)
 	assert.Equal(t, pr.RepoID, ref.RefRepoID)
 	assert.True(t, ref.RefIsPull)
@@ -31,7 +32,7 @@ func TestXRef_AddCrossReferences(t *testing.T) {
 	// Comment on PR to reopen issue #1
 	content = fmt.Sprintf("content2, reopens #%d", itarget.Index)
 	c := testCreateComment(t, 1, 2, pr.ID, content)
-	ref = AssertExistsAndLoadBean(t, &Comment{IssueID: itarget.ID, RefIssueID: pr.ID, RefCommentID: c.ID}).(*Comment)
+	ref = db.AssertExistsAndLoadBean(t, &Comment{IssueID: itarget.ID, RefIssueID: pr.ID, RefCommentID: c.ID}).(*Comment)
 	assert.Equal(t, CommentTypeCommentRef, ref.Type)
 	assert.Equal(t, pr.RepoID, ref.RefRepoID)
 	assert.True(t, ref.RefIsPull)
@@ -40,7 +41,7 @@ func TestXRef_AddCrossReferences(t *testing.T) {
 	// Issue mentioning issue #1
 	content = fmt.Sprintf("content3, mentions #%d", itarget.Index)
 	i := testCreateIssue(t, 1, 2, "title3", content, false)
-	ref = AssertExistsAndLoadBean(t, &Comment{IssueID: itarget.ID, RefIssueID: i.ID, RefCommentID: 0}).(*Comment)
+	ref = db.AssertExistsAndLoadBean(t, &Comment{IssueID: itarget.ID, RefIssueID: i.ID, RefCommentID: 0}).(*Comment)
 	assert.Equal(t, CommentTypeIssueRef, ref.Type)
 	assert.Equal(t, pr.RepoID, ref.RefRepoID)
 	assert.False(t, ref.RefIsPull)
@@ -52,7 +53,7 @@ func TestXRef_AddCrossReferences(t *testing.T) {
 	// Cross-reference to issue #4 by admin
 	content = fmt.Sprintf("content5, mentions user3/repo3#%d", itarget.Index)
 	i = testCreateIssue(t, 2, 1, "title5", content, false)
-	ref = AssertExistsAndLoadBean(t, &Comment{IssueID: itarget.ID, RefIssueID: i.ID, RefCommentID: 0}).(*Comment)
+	ref = db.AssertExistsAndLoadBean(t, &Comment{IssueID: itarget.ID, RefIssueID: i.ID, RefCommentID: 0}).(*Comment)
 	assert.Equal(t, CommentTypeIssueRef, ref.Type)
 	assert.Equal(t, i.RepoID, ref.RefRepoID)
 	assert.False(t, ref.RefIsPull)
@@ -61,11 +62,11 @@ func TestXRef_AddCrossReferences(t *testing.T) {
 	// Cross-reference to issue #4 with no permission
 	content = fmt.Sprintf("content6, mentions user3/repo3#%d", itarget.Index)
 	i = testCreateIssue(t, 4, 5, "title6", content, false)
-	AssertNotExistsBean(t, &Comment{IssueID: itarget.ID, RefIssueID: i.ID, RefCommentID: 0})
+	db.AssertNotExistsBean(t, &Comment{IssueID: itarget.ID, RefIssueID: i.ID, RefCommentID: 0})
 }
 
 func TestXRef_NeuterCrossReferences(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// Issue #1 to test against
 	itarget := testCreateIssue(t, 1, 2, "title1", "content1", false)
@@ -73,23 +74,23 @@ func TestXRef_NeuterCrossReferences(t *testing.T) {
 	// Issue mentioning issue #1
 	title := fmt.Sprintf("title2, mentions #%d", itarget.Index)
 	i := testCreateIssue(t, 1, 2, title, "content2", false)
-	ref := AssertExistsAndLoadBean(t, &Comment{IssueID: itarget.ID, RefIssueID: i.ID, RefCommentID: 0}).(*Comment)
+	ref := db.AssertExistsAndLoadBean(t, &Comment{IssueID: itarget.ID, RefIssueID: i.ID, RefCommentID: 0}).(*Comment)
 	assert.Equal(t, CommentTypeIssueRef, ref.Type)
 	assert.Equal(t, references.XRefActionNone, ref.RefAction)
 
-	d := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	d := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	i.Title = "title2, no mentions"
 	assert.NoError(t, i.ChangeTitle(d, title))
 
-	ref = AssertExistsAndLoadBean(t, &Comment{IssueID: itarget.ID, RefIssueID: i.ID, RefCommentID: 0}).(*Comment)
+	ref = db.AssertExistsAndLoadBean(t, &Comment{IssueID: itarget.ID, RefIssueID: i.ID, RefCommentID: 0}).(*Comment)
 	assert.Equal(t, CommentTypeIssueRef, ref.Type)
 	assert.Equal(t, references.XRefActionNeutered, ref.RefAction)
 }
 
 func TestXRef_ResolveCrossReferences(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	d := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	d := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 
 	i1 := testCreateIssue(t, 1, 2, "title1", "content1", false)
 	i2 := testCreateIssue(t, 1, 2, "title2", "content2", false)
@@ -98,21 +99,21 @@ func TestXRef_ResolveCrossReferences(t *testing.T) {
 	assert.NoError(t, err)
 
 	pr := testCreatePR(t, 1, 2, "titlepr", fmt.Sprintf("closes #%d", i1.Index))
-	rp := AssertExistsAndLoadBean(t, &Comment{IssueID: i1.ID, RefIssueID: pr.Issue.ID, RefCommentID: 0}).(*Comment)
+	rp := db.AssertExistsAndLoadBean(t, &Comment{IssueID: i1.ID, RefIssueID: pr.Issue.ID, RefCommentID: 0}).(*Comment)
 
 	c1 := testCreateComment(t, 1, 2, pr.Issue.ID, fmt.Sprintf("closes #%d", i2.Index))
-	r1 := AssertExistsAndLoadBean(t, &Comment{IssueID: i2.ID, RefIssueID: pr.Issue.ID, RefCommentID: c1.ID}).(*Comment)
+	r1 := db.AssertExistsAndLoadBean(t, &Comment{IssueID: i2.ID, RefIssueID: pr.Issue.ID, RefCommentID: c1.ID}).(*Comment)
 
 	// Must be ignored
 	c2 := testCreateComment(t, 1, 2, pr.Issue.ID, fmt.Sprintf("mentions #%d", i2.Index))
-	AssertExistsAndLoadBean(t, &Comment{IssueID: i2.ID, RefIssueID: pr.Issue.ID, RefCommentID: c2.ID})
+	db.AssertExistsAndLoadBean(t, &Comment{IssueID: i2.ID, RefIssueID: pr.Issue.ID, RefCommentID: c2.ID})
 
 	// Must be superseded by c4/r4
 	c3 := testCreateComment(t, 1, 2, pr.Issue.ID, fmt.Sprintf("reopens #%d", i3.Index))
-	AssertExistsAndLoadBean(t, &Comment{IssueID: i3.ID, RefIssueID: pr.Issue.ID, RefCommentID: c3.ID})
+	db.AssertExistsAndLoadBean(t, &Comment{IssueID: i3.ID, RefIssueID: pr.Issue.ID, RefCommentID: c3.ID})
 
 	c4 := testCreateComment(t, 1, 2, pr.Issue.ID, fmt.Sprintf("closes #%d", i3.Index))
-	r4 := AssertExistsAndLoadBean(t, &Comment{IssueID: i3.ID, RefIssueID: pr.Issue.ID, RefCommentID: c4.ID}).(*Comment)
+	r4 := db.AssertExistsAndLoadBean(t, &Comment{IssueID: i3.ID, RefIssueID: pr.Issue.ID, RefCommentID: c4.ID}).(*Comment)
 
 	refs, err := pr.ResolveCrossReferences()
 	assert.NoError(t, err)
@@ -123,10 +124,10 @@ func TestXRef_ResolveCrossReferences(t *testing.T) {
 }
 
 func testCreateIssue(t *testing.T, repo, doer int64, title, content string, ispull bool) *Issue {
-	r := AssertExistsAndLoadBean(t, &Repository{ID: repo}).(*Repository)
-	d := AssertExistsAndLoadBean(t, &User{ID: doer}).(*User)
+	r := db.AssertExistsAndLoadBean(t, &Repository{ID: repo}).(*Repository)
+	d := db.AssertExistsAndLoadBean(t, &User{ID: doer}).(*User)
 
-	idx, err := GetNextResourceIndex("issue_index", r.ID)
+	idx, err := db.GetNextResourceIndex("issue_index", r.ID)
 	assert.NoError(t, err)
 	i := &Issue{
 		RepoID:   r.ID,
@@ -138,7 +139,7 @@ func testCreateIssue(t *testing.T, repo, doer int64, title, content string, ispu
 		Index:    idx,
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	assert.NoError(t, sess.Begin())
@@ -155,8 +156,8 @@ func testCreateIssue(t *testing.T, repo, doer int64, title, content string, ispu
 }
 
 func testCreatePR(t *testing.T, repo, doer int64, title, content string) *PullRequest {
-	r := AssertExistsAndLoadBean(t, &Repository{ID: repo}).(*Repository)
-	d := AssertExistsAndLoadBean(t, &User{ID: doer}).(*User)
+	r := db.AssertExistsAndLoadBean(t, &Repository{ID: repo}).(*Repository)
+	d := db.AssertExistsAndLoadBean(t, &User{ID: doer}).(*User)
 	i := &Issue{RepoID: r.ID, PosterID: d.ID, Poster: d, Title: title, Content: content, IsPull: true}
 	pr := &PullRequest{HeadRepoID: repo, BaseRepoID: repo, HeadBranch: "head", BaseBranch: "base", Status: PullRequestStatusMergeable}
 	assert.NoError(t, NewPullRequest(r, i, nil, nil, pr))
@@ -165,11 +166,11 @@ func testCreatePR(t *testing.T, repo, doer int64, title, content string) *PullRe
 }
 
 func testCreateComment(t *testing.T, repo, doer, issue int64, content string) *Comment {
-	d := AssertExistsAndLoadBean(t, &User{ID: doer}).(*User)
-	i := AssertExistsAndLoadBean(t, &Issue{ID: issue}).(*Issue)
+	d := db.AssertExistsAndLoadBean(t, &User{ID: doer}).(*User)
+	i := db.AssertExistsAndLoadBean(t, &Issue{ID: issue}).(*Issue)
 	c := &Comment{Type: CommentTypeComment, PosterID: doer, Poster: d, IssueID: issue, Issue: i, Content: content}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	assert.NoError(t, sess.Begin())
 	_, err := sess.Insert(c)
diff --git a/models/lfs.go b/models/lfs.go
index c8abb1cd4..a856873e7 100644
--- a/models/lfs.go
+++ b/models/lfs.go
@@ -7,6 +7,7 @@ package models
 import (
 	"errors"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/lfs"
 	"code.gitea.io/gitea/modules/timeutil"
 
@@ -22,6 +23,10 @@ type LFSMetaObject struct {
 	CreatedUnix  timeutil.TimeStamp `xorm:"created"`
 }
 
+func init() {
+	db.RegisterModel(new(LFSMetaObject))
+}
+
 // LFSTokenResponse defines the JSON structure in which the JWT token is stored.
 // This structure is fetched via SSH and passed by the Git LFS client to the server
 // endpoint for authorization.
@@ -39,7 +44,7 @@ var ErrLFSObjectNotExist = errors.New("LFS Meta object does not exist")
 func NewLFSMetaObject(m *LFSMetaObject) (*LFSMetaObject, error) {
 	var err error
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return nil, err
@@ -71,7 +76,7 @@ func (repo *Repository) GetLFSMetaObjectByOid(oid string) (*LFSMetaObject, error
 	}
 
 	m := &LFSMetaObject{Pointer: lfs.Pointer{Oid: oid}, RepositoryID: repo.ID}
-	has, err := x.Get(m)
+	has, err := db.DefaultContext().Engine().Get(m)
 	if err != nil {
 		return nil, err
 	} else if !has {
@@ -87,7 +92,7 @@ func (repo *Repository) RemoveLFSMetaObjectByOid(oid string) (int64, error) {
 		return 0, ErrLFSObjectNotExist
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return -1, err
@@ -108,7 +113,7 @@ func (repo *Repository) RemoveLFSMetaObjectByOid(oid string) (int64, error) {
 
 // GetLFSMetaObjects returns all LFSMetaObjects associated with a repository
 func (repo *Repository) GetLFSMetaObjects(page, pageSize int) ([]*LFSMetaObject, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	if page >= 0 && pageSize > 0 {
@@ -124,23 +129,23 @@ func (repo *Repository) GetLFSMetaObjects(page, pageSize int) ([]*LFSMetaObject,
 
 // CountLFSMetaObjects returns a count of all LFSMetaObjects associated with a repository
 func (repo *Repository) CountLFSMetaObjects() (int64, error) {
-	return x.Count(&LFSMetaObject{RepositoryID: repo.ID})
+	return db.DefaultContext().Engine().Count(&LFSMetaObject{RepositoryID: repo.ID})
 }
 
 // LFSObjectAccessible checks if a provided Oid is accessible to the user
 func LFSObjectAccessible(user *User, oid string) (bool, error) {
 	if user.IsAdmin {
-		count, err := x.Count(&LFSMetaObject{Pointer: lfs.Pointer{Oid: oid}})
+		count, err := db.DefaultContext().Engine().Count(&LFSMetaObject{Pointer: lfs.Pointer{Oid: oid}})
 		return count > 0, err
 	}
 	cond := accessibleRepositoryCondition(user)
-	count, err := x.Where(cond).Join("INNER", "repository", "`lfs_meta_object`.repository_id = `repository`.id").Count(&LFSMetaObject{Pointer: lfs.Pointer{Oid: oid}})
+	count, err := db.DefaultContext().Engine().Where(cond).Join("INNER", "repository", "`lfs_meta_object`.repository_id = `repository`.id").Count(&LFSMetaObject{Pointer: lfs.Pointer{Oid: oid}})
 	return count > 0, err
 }
 
 // LFSAutoAssociate auto associates accessible LFSMetaObjects
 func LFSAutoAssociate(metas []*LFSMetaObject, user *User, repoID int64) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -179,7 +184,7 @@ func IterateLFS(f func(mo *LFSMetaObject) error) error {
 	const batchSize = 100
 	for {
 		mos := make([]*LFSMetaObject, 0, batchSize)
-		if err := x.Limit(batchSize, start).Find(&mos); err != nil {
+		if err := db.DefaultContext().Engine().Limit(batchSize, start).Find(&mos); err != nil {
 			return err
 		}
 		if len(mos) == 0 {
diff --git a/models/lfs_lock.go b/models/lfs_lock.go
index 6c3d7c87c..d7efdf444 100644
--- a/models/lfs_lock.go
+++ b/models/lfs_lock.go
@@ -10,6 +10,7 @@ import (
 	"strings"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 
 	"xorm.io/xorm"
@@ -26,6 +27,10 @@ type LFSLock struct {
 	Created time.Time   `xorm:"created"`
 }
 
+func init() {
+	db.RegisterModel(new(LFSLock))
+}
+
 // BeforeInsert is invoked from XORM before inserting an object of this type.
 func (l *LFSLock) BeforeInsert() {
 	l.OwnerID = l.Owner.ID
@@ -67,7 +72,7 @@ func CreateLFSLock(lock *LFSLock) (*LFSLock, error) {
 		return nil, err
 	}
 
-	_, err = x.InsertOne(lock)
+	_, err = db.DefaultContext().Engine().InsertOne(lock)
 	return lock, err
 }
 
@@ -75,7 +80,7 @@ func CreateLFSLock(lock *LFSLock) (*LFSLock, error) {
 func GetLFSLock(repo *Repository, path string) (*LFSLock, error) {
 	path = cleanPath(path)
 	rel := &LFSLock{RepoID: repo.ID}
-	has, err := x.Where("lower(path) = ?", strings.ToLower(path)).Get(rel)
+	has, err := db.DefaultContext().Engine().Where("lower(path) = ?", strings.ToLower(path)).Get(rel)
 	if err != nil {
 		return nil, err
 	}
@@ -88,7 +93,7 @@ func GetLFSLock(repo *Repository, path string) (*LFSLock, error) {
 // GetLFSLockByID returns release by given id.
 func GetLFSLockByID(id int64) (*LFSLock, error) {
 	lock := new(LFSLock)
-	has, err := x.ID(id).Get(lock)
+	has, err := db.DefaultContext().Engine().ID(id).Get(lock)
 	if err != nil {
 		return nil, err
 	} else if !has {
@@ -99,7 +104,7 @@ func GetLFSLockByID(id int64) (*LFSLock, error) {
 
 // GetLFSLockByRepoID returns a list of locks of repository.
 func GetLFSLockByRepoID(repoID int64, page, pageSize int) ([]*LFSLock, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	if page >= 0 && pageSize > 0 {
@@ -115,7 +120,7 @@ func GetLFSLockByRepoID(repoID int64, page, pageSize int) ([]*LFSLock, error) {
 
 // CountLFSLockByRepoID returns a count of all LFSLocks associated with a repository.
 func CountLFSLockByRepoID(repoID int64) (int64, error) {
-	return x.Count(&LFSLock{RepoID: repoID})
+	return db.DefaultContext().Engine().Count(&LFSLock{RepoID: repoID})
 }
 
 // DeleteLFSLockByID deletes a lock by given ID.
@@ -134,7 +139,7 @@ func DeleteLFSLockByID(id int64, u *User, force bool) (*LFSLock, error) {
 		return nil, fmt.Errorf("user doesn't own lock and force flag is not set")
 	}
 
-	_, err = x.ID(id).Delete(new(LFSLock))
+	_, err = db.DefaultContext().Engine().ID(id).Delete(new(LFSLock))
 	return lock, err
 }
 
diff --git a/models/list_options.go b/models/list_options.go
index 8b6196793..59bfa9167 100644
--- a/models/list_options.go
+++ b/models/list_options.go
@@ -5,6 +5,7 @@
 package models
 
 import (
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 
 	"xorm.io/xorm"
@@ -20,7 +21,7 @@ type Paginator interface {
 func getPaginatedSession(p Paginator) *xorm.Session {
 	skip, take := p.GetSkipTake()
 
-	return x.Limit(take, skip)
+	return db.DefaultContext().Engine().Limit(take, skip)
 }
 
 // setSessionPagination sets pagination for a database session
@@ -31,7 +32,7 @@ func setSessionPagination(sess *xorm.Session, p Paginator) *xorm.Session {
 }
 
 // setSessionPagination sets pagination for a database engine
-func setEnginePagination(e Engine, p Paginator) Engine {
+func setEnginePagination(e db.Engine, p Paginator) db.Engine {
 	skip, take := p.GetSkipTake()
 
 	return e.Limit(take, skip)
diff --git a/models/login_source.go b/models/login_source.go
index 3a48074e9..77a43fe4a 100644
--- a/models/login_source.go
+++ b/models/login_source.go
@@ -9,6 +9,7 @@ import (
 	"reflect"
 	"strconv"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/timeutil"
 
@@ -118,6 +119,10 @@ type LoginSource struct {
 	UpdatedUnix timeutil.TimeStamp `xorm:"INDEX updated"`
 }
 
+func init() {
+	db.RegisterModel(new(LoginSource))
+}
+
 // Cell2Int64 converts a xorm.Cell type to int64,
 // and handles possible irregular cases.
 func Cell2Int64(val xorm.Cell) int64 {
@@ -203,7 +208,7 @@ func (source *LoginSource) SkipVerify() bool {
 // CreateLoginSource inserts a LoginSource in the DB if not already
 // existing with the given name.
 func CreateLoginSource(source *LoginSource) error {
-	has, err := x.Where("name=?", source.Name).Exist(new(LoginSource))
+	has, err := db.DefaultContext().Engine().Where("name=?", source.Name).Exist(new(LoginSource))
 	if err != nil {
 		return err
 	} else if has {
@@ -214,7 +219,7 @@ func CreateLoginSource(source *LoginSource) error {
 		source.IsSyncEnabled = false
 	}
 
-	_, err = x.Insert(source)
+	_, err = db.DefaultContext().Engine().Insert(source)
 	if err != nil {
 		return err
 	}
@@ -235,7 +240,7 @@ func CreateLoginSource(source *LoginSource) error {
 	err = registerableSource.RegisterSource()
 	if err != nil {
 		// remove the LoginSource in case of errors while registering configuration
-		if _, err := x.Delete(source); err != nil {
+		if _, err := db.DefaultContext().Engine().Delete(source); err != nil {
 			log.Error("CreateLoginSource: Error while wrapOpenIDConnectInitializeError: %v", err)
 		}
 	}
@@ -245,13 +250,13 @@ func CreateLoginSource(source *LoginSource) error {
 // LoginSources returns a slice of all login sources found in DB.
 func LoginSources() ([]*LoginSource, error) {
 	auths := make([]*LoginSource, 0, 6)
-	return auths, x.Find(&auths)
+	return auths, db.DefaultContext().Engine().Find(&auths)
 }
 
 // LoginSourcesByType returns all sources of the specified type
 func LoginSourcesByType(loginType LoginType) ([]*LoginSource, error) {
 	sources := make([]*LoginSource, 0, 1)
-	if err := x.Where("type = ?", loginType).Find(&sources); err != nil {
+	if err := db.DefaultContext().Engine().Where("type = ?", loginType).Find(&sources); err != nil {
 		return nil, err
 	}
 	return sources, nil
@@ -260,7 +265,7 @@ func LoginSourcesByType(loginType LoginType) ([]*LoginSource, error) {
 // AllActiveLoginSources returns all active sources
 func AllActiveLoginSources() ([]*LoginSource, error) {
 	sources := make([]*LoginSource, 0, 5)
-	if err := x.Where("is_active = ?", true).Find(&sources); err != nil {
+	if err := db.DefaultContext().Engine().Where("is_active = ?", true).Find(&sources); err != nil {
 		return nil, err
 	}
 	return sources, nil
@@ -269,7 +274,7 @@ func AllActiveLoginSources() ([]*LoginSource, error) {
 // ActiveLoginSources returns all active sources of the specified type
 func ActiveLoginSources(loginType LoginType) ([]*LoginSource, error) {
 	sources := make([]*LoginSource, 0, 1)
-	if err := x.Where("is_active = ? and type = ?", true, loginType).Find(&sources); err != nil {
+	if err := db.DefaultContext().Engine().Where("is_active = ? and type = ?", true, loginType).Find(&sources); err != nil {
 		return nil, err
 	}
 	return sources, nil
@@ -278,7 +283,7 @@ func ActiveLoginSources(loginType LoginType) ([]*LoginSource, error) {
 // IsSSPIEnabled returns true if there is at least one activated login
 // source of type LoginSSPI
 func IsSSPIEnabled() bool {
-	if !HasEngine {
+	if !db.HasEngine {
 		return false
 	}
 	sources, err := ActiveLoginSources(LoginSSPI)
@@ -300,7 +305,7 @@ func GetLoginSourceByID(id int64) (*LoginSource, error) {
 		return source, nil
 	}
 
-	has, err := x.ID(id).Get(source)
+	has, err := db.DefaultContext().Engine().ID(id).Get(source)
 	if err != nil {
 		return nil, err
 	} else if !has {
@@ -320,7 +325,7 @@ func UpdateSource(source *LoginSource) error {
 		}
 	}
 
-	_, err := x.ID(source.ID).AllCols().Update(source)
+	_, err := db.DefaultContext().Engine().ID(source.ID).AllCols().Update(source)
 	if err != nil {
 		return err
 	}
@@ -341,7 +346,7 @@ func UpdateSource(source *LoginSource) error {
 	err = registerableSource.RegisterSource()
 	if err != nil {
 		// restore original values since we cannot update the provider it self
-		if _, err := x.ID(source.ID).AllCols().Update(originalLoginSource); err != nil {
+		if _, err := db.DefaultContext().Engine().ID(source.ID).AllCols().Update(originalLoginSource); err != nil {
 			log.Error("UpdateSource: Error while wrapOpenIDConnectInitializeError: %v", err)
 		}
 	}
@@ -350,14 +355,14 @@ func UpdateSource(source *LoginSource) error {
 
 // DeleteSource deletes a LoginSource record in DB.
 func DeleteSource(source *LoginSource) error {
-	count, err := x.Count(&User{LoginSource: source.ID})
+	count, err := db.DefaultContext().Engine().Count(&User{LoginSource: source.ID})
 	if err != nil {
 		return err
 	} else if count > 0 {
 		return ErrLoginSourceInUse{source.ID}
 	}
 
-	count, err = x.Count(&ExternalLoginUser{LoginSourceID: source.ID})
+	count, err = db.DefaultContext().Engine().Count(&ExternalLoginUser{LoginSourceID: source.ID})
 	if err != nil {
 		return err
 	} else if count > 0 {
@@ -370,12 +375,12 @@ func DeleteSource(source *LoginSource) error {
 		}
 	}
 
-	_, err = x.ID(source.ID).Delete(new(LoginSource))
+	_, err = db.DefaultContext().Engine().ID(source.ID).Delete(new(LoginSource))
 	return err
 }
 
 // CountLoginSources returns number of login sources.
 func CountLoginSources() int64 {
-	count, _ := x.Count(new(LoginSource))
+	count, _ := db.DefaultContext().Engine().Count(new(LoginSource))
 	return count
 }
diff --git a/models/models_test.go b/models/login_source_test.go
similarity index 62%
rename from models/models_test.go
rename to models/login_source_test.go
index c75c299e4..ea1812238 100644
--- a/models/models_test.go
+++ b/models/login_source_test.go
@@ -5,37 +5,16 @@
 package models
 
 import (
-	"encoding/json"
-	"io/ioutil"
-	"os"
-	"path/filepath"
 	"strings"
 	"testing"
 
-	"code.gitea.io/gitea/modules/setting"
-	"xorm.io/xorm/schemas"
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/modules/json"
 
 	"github.com/stretchr/testify/assert"
+	"xorm.io/xorm/schemas"
 )
 
-func TestDumpDatabase(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-
-	dir, err := ioutil.TempDir(os.TempDir(), "dump")
-	assert.NoError(t, err)
-
-	type Version struct {
-		ID      int64 `xorm:"pk autoincr"`
-		Version int64
-	}
-	assert.NoError(t, x.Sync2(new(Version)))
-
-	for _, dbName := range setting.SupportedDatabases {
-		dbType := setting.GetDBTypeByName(dbName)
-		assert.NoError(t, DumpDatabase(filepath.Join(dir, dbType+".sql"), dbType))
-	}
-}
-
 type TestSource struct {
 	Provider                      string
 	ClientID                      string
@@ -55,9 +34,9 @@ func (source *TestSource) ToDB() ([]byte, error) {
 }
 
 func TestDumpLoginSource(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	loginSourceSchema, err := x.TableInfo(new(LoginSource))
+	loginSourceSchema, err := db.TableInfo(new(LoginSource))
 	assert.NoError(t, err)
 
 	RegisterLoginTypeConfig(LoginOAuth2, new(TestSource))
@@ -74,7 +53,7 @@ func TestDumpLoginSource(t *testing.T) {
 
 	sb := new(strings.Builder)
 
-	x.DumpTables([]*schemas.Table{loginSourceSchema}, sb)
+	db.DumpTables([]*schemas.Table{loginSourceSchema}, sb)
 
 	assert.Contains(t, sb.String(), `"Provider":"ConvertibleSourceName"`)
 }
diff --git a/models/main_test.go b/models/main_test.go
index 78fc78b4d..ad9276330 100644
--- a/models/main_test.go
+++ b/models/main_test.go
@@ -7,15 +7,17 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
+
 	"github.com/stretchr/testify/assert"
 )
 
 // TestFixturesAreConsistent assert that test fixtures are consistent
 func TestFixturesAreConsistent(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	CheckConsistencyForAll(t)
 }
 
 func TestMain(m *testing.M) {
-	MainTest(m, "..")
+	db.MainTest(m, "..")
 }
diff --git a/models/migrate.go b/models/migrate.go
index 28b670747..163573a16 100644
--- a/models/migrate.go
+++ b/models/migrate.go
@@ -5,6 +5,7 @@
 package models
 
 import (
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/structs"
 
 	"xorm.io/builder"
@@ -17,7 +18,7 @@ func InsertMilestones(ms ...*Milestone) (err error) {
 		return nil
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -38,7 +39,7 @@ func InsertMilestones(ms ...*Milestone) (err error) {
 
 // InsertIssues insert issues to database
 func InsertIssues(issues ...*Issue) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -143,7 +144,7 @@ func InsertIssueComments(comments []*Comment) error {
 		issueIDs[comment.IssueID] = true
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -174,7 +175,7 @@ func InsertIssueComments(comments []*Comment) error {
 
 // InsertPullRequests inserted pull requests
 func InsertPullRequests(prs ...*PullRequest) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -194,7 +195,7 @@ func InsertPullRequests(prs ...*PullRequest) error {
 
 // InsertReleases migrates release
 func InsertReleases(rels ...*Release) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -232,7 +233,7 @@ func migratedIssueCond(tp structs.GitServiceType) builder.Cond {
 
 // UpdateReviewsMigrationsByType updates reviews' migrations information via given git service type and original id and poster id
 func UpdateReviewsMigrationsByType(tp structs.GitServiceType, originalAuthorID string, posterID int64) error {
-	_, err := x.Table("review").
+	_, err := db.DefaultContext().Engine().Table("review").
 		Where("original_author_id = ?", originalAuthorID).
 		And(migratedIssueCond(tp)).
 		Update(map[string]interface{}{
diff --git a/models/migrations/migrations_test.go b/models/migrations/migrations_test.go
index 634bfc848..fffc44be1 100644
--- a/models/migrations/migrations_test.go
+++ b/models/migrations/migrations_test.go
@@ -14,12 +14,13 @@ import (
 	"testing"
 	"time"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/util"
+
 	"github.com/stretchr/testify/assert"
 	"github.com/unknwon/com"
 	"xorm.io/xorm"
@@ -85,7 +86,7 @@ func removeAllWithRetry(dir string) error {
 
 // SetEngine sets the xorm.Engine
 func SetEngine() (*xorm.Engine, error) {
-	x, err := models.GetNewEngine()
+	x, err := db.GetNewEngine()
 	if err != nil {
 		return x, fmt.Errorf("Failed to connect to database: %v", err)
 	}
@@ -93,7 +94,7 @@ func SetEngine() (*xorm.Engine, error) {
 	x.SetMapper(names.GonicMapper{})
 	// WARNING: for serv command, MUST remove the output to os.stdout,
 	// so use log file to instead print to stdout.
-	x.SetLogger(models.NewXORMLogger(setting.Database.LogSQL))
+	x.SetLogger(db.NewXORMLogger(setting.Database.LogSQL))
 	x.ShowSQL(setting.Database.LogSQL)
 	x.SetMaxOpenConns(setting.Database.MaxOpenConns)
 	x.SetMaxIdleConns(setting.Database.MaxIdleConns)
@@ -240,11 +241,11 @@ func prepareTestEnv(t *testing.T, skip int, syncModels ...interface{}) (*xorm.En
 
 	if _, err := os.Stat(fixturesDir); err == nil {
 		t.Logf("initializing fixtures from: %s", fixturesDir)
-		if err := models.InitFixtures(fixturesDir, x); err != nil {
+		if err := db.InitFixtures(fixturesDir, x); err != nil {
 			t.Errorf("error whilst initializing fixtures from %s: %v", fixturesDir, err)
 			return x, deferFn
 		}
-		if err := models.LoadFixtures(x); err != nil {
+		if err := db.LoadFixtures(x); err != nil {
 			t.Errorf("error whilst loading fixtures from %s: %v", fixturesDir, err)
 			return x, deferFn
 		}
diff --git a/models/notification.go b/models/notification.go
index fcd0c57db..2f34def07 100644
--- a/models/notification.go
+++ b/models/notification.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"strconv"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/timeutil"
@@ -67,6 +68,10 @@ type Notification struct {
 	UpdatedUnix timeutil.TimeStamp `xorm:"updated INDEX NOT NULL"`
 }
 
+func init() {
+	db.RegisterModel(new(Notification))
+}
+
 // FindNotificationOptions represent the filters for notifications. If an ID is 0 it will be ignored.
 type FindNotificationOptions struct {
 	ListOptions
@@ -107,7 +112,7 @@ func (opts *FindNotificationOptions) ToCond() builder.Cond {
 }
 
 // ToSession will convert the given options to a xorm Session by using the conditions from ToCond and joining with issue table if required
-func (opts *FindNotificationOptions) ToSession(e Engine) *xorm.Session {
+func (opts *FindNotificationOptions) ToSession(e db.Engine) *xorm.Session {
 	sess := e.Where(opts.ToCond())
 	if opts.Page != 0 {
 		sess = setSessionPagination(sess, opts)
@@ -115,24 +120,24 @@ func (opts *FindNotificationOptions) ToSession(e Engine) *xorm.Session {
 	return sess
 }
 
-func getNotifications(e Engine, options *FindNotificationOptions) (nl NotificationList, err error) {
+func getNotifications(e db.Engine, options *FindNotificationOptions) (nl NotificationList, err error) {
 	err = options.ToSession(e).OrderBy("notification.updated_unix DESC").Find(&nl)
 	return
 }
 
 // GetNotifications returns all notifications that fit to the given options.
 func GetNotifications(opts *FindNotificationOptions) (NotificationList, error) {
-	return getNotifications(x, opts)
+	return getNotifications(db.DefaultContext().Engine(), opts)
 }
 
 // CountNotifications count all notifications that fit to the given options and ignore pagination.
 func CountNotifications(opts *FindNotificationOptions) (int64, error) {
-	return x.Where(opts.ToCond()).Count(&Notification{})
+	return db.DefaultContext().Engine().Where(opts.ToCond()).Count(&Notification{})
 }
 
 // CreateRepoTransferNotification creates  notification for the user a repository was transferred to
 func CreateRepoTransferNotification(doer, newOwner *User, repo *Repository) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -174,7 +179,7 @@ func CreateRepoTransferNotification(doer, newOwner *User, repo *Repository) erro
 // for each watcher, or updates it if already exists
 // receiverID > 0 just send to reciver, else send to all watcher
 func CreateOrUpdateIssueNotifications(issueID, commentID, notificationAuthorID, receiverID int64) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -187,7 +192,7 @@ func CreateOrUpdateIssueNotifications(issueID, commentID, notificationAuthorID,
 	return sess.Commit()
 }
 
-func createOrUpdateIssueNotifications(e Engine, issueID, commentID, notificationAuthorID, receiverID int64) error {
+func createOrUpdateIssueNotifications(e db.Engine, issueID, commentID, notificationAuthorID, receiverID int64) error {
 	// init
 	var toNotify map[int64]struct{}
 	notifications, err := getNotificationsByIssueID(e, issueID)
@@ -277,7 +282,7 @@ func createOrUpdateIssueNotifications(e Engine, issueID, commentID, notification
 	return nil
 }
 
-func getNotificationsByIssueID(e Engine, issueID int64) (notifications []*Notification, err error) {
+func getNotificationsByIssueID(e db.Engine, issueID int64) (notifications []*Notification, err error) {
 	err = e.
 		Where("issue_id = ?", issueID).
 		Find(&notifications)
@@ -294,7 +299,7 @@ func notificationExists(notifications []*Notification, issueID, userID int64) bo
 	return false
 }
 
-func createIssueNotification(e Engine, userID int64, issue *Issue, commentID, updatedByID int64) error {
+func createIssueNotification(e db.Engine, userID int64, issue *Issue, commentID, updatedByID int64) error {
 	notification := &Notification{
 		UserID:    userID,
 		RepoID:    issue.RepoID,
@@ -314,7 +319,7 @@ func createIssueNotification(e Engine, userID int64, issue *Issue, commentID, up
 	return err
 }
 
-func updateIssueNotification(e Engine, userID, issueID, commentID, updatedByID int64) error {
+func updateIssueNotification(e db.Engine, userID, issueID, commentID, updatedByID int64) error {
 	notification, err := getIssueNotification(e, userID, issueID)
 	if err != nil {
 		return err
@@ -336,7 +341,7 @@ func updateIssueNotification(e Engine, userID, issueID, commentID, updatedByID i
 	return err
 }
 
-func getIssueNotification(e Engine, userID, issueID int64) (*Notification, error) {
+func getIssueNotification(e db.Engine, userID, issueID int64) (*Notification, error) {
 	notification := new(Notification)
 	_, err := e.
 		Where("user_id = ?", userID).
@@ -347,10 +352,10 @@ func getIssueNotification(e Engine, userID, issueID int64) (*Notification, error
 
 // NotificationsForUser returns notifications for a given user and status
 func NotificationsForUser(user *User, statuses []NotificationStatus, page, perPage int) (NotificationList, error) {
-	return notificationsForUser(x, user, statuses, page, perPage)
+	return notificationsForUser(db.DefaultContext().Engine(), user, statuses, page, perPage)
 }
 
-func notificationsForUser(e Engine, user *User, statuses []NotificationStatus, page, perPage int) (notifications []*Notification, err error) {
+func notificationsForUser(e db.Engine, user *User, statuses []NotificationStatus, page, perPage int) (notifications []*Notification, err error) {
 	if len(statuses) == 0 {
 		return
 	}
@@ -370,10 +375,10 @@ func notificationsForUser(e Engine, user *User, statuses []NotificationStatus, p
 
 // CountUnread count unread notifications for a user
 func CountUnread(user *User) int64 {
-	return countUnread(x, user.ID)
+	return countUnread(db.DefaultContext().Engine(), user.ID)
 }
 
-func countUnread(e Engine, userID int64) int64 {
+func countUnread(e db.Engine, userID int64) int64 {
 	exist, err := e.Where("user_id = ?", userID).And("status = ?", NotificationStatusUnread).Count(new(Notification))
 	if err != nil {
 		log.Error("countUnread", err)
@@ -384,10 +389,10 @@ func countUnread(e Engine, userID int64) int64 {
 
 // LoadAttributes load Repo Issue User and Comment if not loaded
 func (n *Notification) LoadAttributes() (err error) {
-	return n.loadAttributes(x)
+	return n.loadAttributes(db.DefaultContext().Engine())
 }
 
-func (n *Notification) loadAttributes(e Engine) (err error) {
+func (n *Notification) loadAttributes(e db.Engine) (err error) {
 	if err = n.loadRepo(e); err != nil {
 		return
 	}
@@ -403,7 +408,7 @@ func (n *Notification) loadAttributes(e Engine) (err error) {
 	return
 }
 
-func (n *Notification) loadRepo(e Engine) (err error) {
+func (n *Notification) loadRepo(e db.Engine) (err error) {
 	if n.Repository == nil {
 		n.Repository, err = getRepositoryByID(e, n.RepoID)
 		if err != nil {
@@ -413,7 +418,7 @@ func (n *Notification) loadRepo(e Engine) (err error) {
 	return nil
 }
 
-func (n *Notification) loadIssue(e Engine) (err error) {
+func (n *Notification) loadIssue(e db.Engine) (err error) {
 	if n.Issue == nil && n.IssueID != 0 {
 		n.Issue, err = getIssueByID(e, n.IssueID)
 		if err != nil {
@@ -424,7 +429,7 @@ func (n *Notification) loadIssue(e Engine) (err error) {
 	return nil
 }
 
-func (n *Notification) loadComment(e Engine) (err error) {
+func (n *Notification) loadComment(e db.Engine) (err error) {
 	if n.Comment == nil && n.CommentID != 0 {
 		n.Comment, err = getCommentByID(e, n.CommentID)
 		if err != nil {
@@ -434,7 +439,7 @@ func (n *Notification) loadComment(e Engine) (err error) {
 	return nil
 }
 
-func (n *Notification) loadUser(e Engine) (err error) {
+func (n *Notification) loadUser(e db.Engine) (err error) {
 	if n.User == nil {
 		n.User, err = getUserByID(e, n.UserID)
 		if err != nil {
@@ -446,12 +451,12 @@ func (n *Notification) loadUser(e Engine) (err error) {
 
 // GetRepo returns the repo of the notification
 func (n *Notification) GetRepo() (*Repository, error) {
-	return n.Repository, n.loadRepo(x)
+	return n.Repository, n.loadRepo(db.DefaultContext().Engine())
 }
 
 // GetIssue returns the issue of the notification
 func (n *Notification) GetIssue() (*Issue, error) {
-	return n.Issue, n.loadIssue(x)
+	return n.Issue, n.loadIssue(db.DefaultContext().Engine())
 }
 
 // HTMLURL formats a URL-string to the notification
@@ -516,7 +521,7 @@ func (nl NotificationList) LoadRepos() (RepositoryList, []int, error) {
 		if left < limit {
 			limit = left
 		}
-		rows, err := x.
+		rows, err := db.DefaultContext().Engine().
 			In("id", repoIDs[:limit]).
 			Rows(new(Repository))
 		if err != nil {
@@ -592,7 +597,7 @@ func (nl NotificationList) LoadIssues() ([]int, error) {
 		if left < limit {
 			limit = left
 		}
-		rows, err := x.
+		rows, err := db.DefaultContext().Engine().
 			In("id", issueIDs[:limit]).
 			Rows(new(Issue))
 		if err != nil {
@@ -678,7 +683,7 @@ func (nl NotificationList) LoadComments() ([]int, error) {
 		if left < limit {
 			limit = left
 		}
-		rows, err := x.
+		rows, err := db.DefaultContext().Engine().
 			In("id", commentIDs[:limit]).
 			Rows(new(Comment))
 		if err != nil {
@@ -718,10 +723,10 @@ func (nl NotificationList) LoadComments() ([]int, error) {
 
 // GetNotificationCount returns the notification count for user
 func GetNotificationCount(user *User, status NotificationStatus) (int64, error) {
-	return getNotificationCount(x, user, status)
+	return getNotificationCount(db.DefaultContext().Engine(), user, status)
 }
 
-func getNotificationCount(e Engine, user *User, status NotificationStatus) (count int64, err error) {
+func getNotificationCount(e db.Engine, user *User, status NotificationStatus) (count int64, err error) {
 	count, err = e.
 		Where("user_id = ?", user.ID).
 		And("status = ?", status).
@@ -741,10 +746,10 @@ func GetUIDsAndNotificationCounts(since, until timeutil.TimeStamp) ([]UserIDCoun
 		`WHERE user_id IN (SELECT user_id FROM notification WHERE updated_unix >= ? AND ` +
 		`updated_unix < ?) AND status = ? GROUP BY user_id`
 	var res []UserIDCount
-	return res, x.SQL(sql, since, until, NotificationStatusUnread).Find(&res)
+	return res, db.DefaultContext().Engine().SQL(sql, since, until, NotificationStatusUnread).Find(&res)
 }
 
-func setIssueNotificationStatusReadIfUnread(e Engine, userID, issueID int64) error {
+func setIssueNotificationStatusReadIfUnread(e db.Engine, userID, issueID int64) error {
 	notification, err := getIssueNotification(e, userID, issueID)
 	// ignore if not exists
 	if err != nil {
@@ -761,7 +766,7 @@ func setIssueNotificationStatusReadIfUnread(e Engine, userID, issueID int64) err
 	return err
 }
 
-func setRepoNotificationStatusReadIfUnread(e Engine, userID, repoID int64) error {
+func setRepoNotificationStatusReadIfUnread(e db.Engine, userID, repoID int64) error {
 	_, err := e.Where(builder.Eq{
 		"user_id": userID,
 		"status":  NotificationStatusUnread,
@@ -773,7 +778,7 @@ func setRepoNotificationStatusReadIfUnread(e Engine, userID, repoID int64) error
 
 // SetNotificationStatus change the notification status
 func SetNotificationStatus(notificationID int64, user *User, status NotificationStatus) (*Notification, error) {
-	notification, err := getNotificationByID(x, notificationID)
+	notification, err := getNotificationByID(db.DefaultContext().Engine(), notificationID)
 	if err != nil {
 		return notification, err
 	}
@@ -784,16 +789,16 @@ func SetNotificationStatus(notificationID int64, user *User, status Notification
 
 	notification.Status = status
 
-	_, err = x.ID(notificationID).Update(notification)
+	_, err = db.DefaultContext().Engine().ID(notificationID).Update(notification)
 	return notification, err
 }
 
 // GetNotificationByID return notification by ID
 func GetNotificationByID(notificationID int64) (*Notification, error) {
-	return getNotificationByID(x, notificationID)
+	return getNotificationByID(db.DefaultContext().Engine(), notificationID)
 }
 
-func getNotificationByID(e Engine, notificationID int64) (*Notification, error) {
+func getNotificationByID(e db.Engine, notificationID int64) (*Notification, error) {
 	notification := new(Notification)
 	ok, err := e.
 		Where("id = ?", notificationID).
@@ -812,7 +817,7 @@ func getNotificationByID(e Engine, notificationID int64) (*Notification, error)
 // UpdateNotificationStatuses updates the statuses of all of a user's notifications that are of the currentStatus type to the desiredStatus
 func UpdateNotificationStatuses(user *User, currentStatus, desiredStatus NotificationStatus) error {
 	n := &Notification{Status: desiredStatus, UpdatedBy: user.ID}
-	_, err := x.
+	_, err := db.DefaultContext().Engine().
 		Where("user_id = ? AND status = ?", user.ID, currentStatus).
 		Cols("status", "updated_by", "updated_unix").
 		Update(n)
diff --git a/models/notification_test.go b/models/notification_test.go
index 440b6ed4c..588882bed 100644
--- a/models/notification_test.go
+++ b/models/notification_test.go
@@ -7,27 +7,28 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestCreateOrUpdateIssueNotifications(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	issue := AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
+	assert.NoError(t, db.PrepareTestDatabase())
+	issue := db.AssertExistsAndLoadBean(t, &Issue{ID: 1}).(*Issue)
 
 	assert.NoError(t, CreateOrUpdateIssueNotifications(issue.ID, 0, 2, 0))
 
 	// User 9 is inactive, thus notifications for user 1 and 4 are created
-	notf := AssertExistsAndLoadBean(t, &Notification{UserID: 1, IssueID: issue.ID}).(*Notification)
+	notf := db.AssertExistsAndLoadBean(t, &Notification{UserID: 1, IssueID: issue.ID}).(*Notification)
 	assert.Equal(t, NotificationStatusUnread, notf.Status)
 	CheckConsistencyFor(t, &Issue{ID: issue.ID})
 
-	notf = AssertExistsAndLoadBean(t, &Notification{UserID: 4, IssueID: issue.ID}).(*Notification)
+	notf = db.AssertExistsAndLoadBean(t, &Notification{UserID: 4, IssueID: issue.ID}).(*Notification)
 	assert.Equal(t, NotificationStatusUnread, notf.Status)
 }
 
 func TestNotificationsForUser(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	user := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	statuses := []NotificationStatus{NotificationStatusRead, NotificationStatusUnread}
 	notfs, err := NotificationsForUser(user, statuses, 1, 10)
 	assert.NoError(t, err)
@@ -42,8 +43,8 @@ func TestNotificationsForUser(t *testing.T) {
 }
 
 func TestNotification_GetRepo(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	notf := AssertExistsAndLoadBean(t, &Notification{RepoID: 1}).(*Notification)
+	assert.NoError(t, db.PrepareTestDatabase())
+	notf := db.AssertExistsAndLoadBean(t, &Notification{RepoID: 1}).(*Notification)
 	repo, err := notf.GetRepo()
 	assert.NoError(t, err)
 	assert.Equal(t, repo, notf.Repository)
@@ -51,8 +52,8 @@ func TestNotification_GetRepo(t *testing.T) {
 }
 
 func TestNotification_GetIssue(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	notf := AssertExistsAndLoadBean(t, &Notification{RepoID: 1}).(*Notification)
+	assert.NoError(t, db.PrepareTestDatabase())
+	notf := db.AssertExistsAndLoadBean(t, &Notification{RepoID: 1}).(*Notification)
 	issue, err := notf.GetIssue()
 	assert.NoError(t, err)
 	assert.Equal(t, issue, notf.Issue)
@@ -60,8 +61,8 @@ func TestNotification_GetIssue(t *testing.T) {
 }
 
 func TestGetNotificationCount(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	user := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 	cnt, err := GetNotificationCount(user, NotificationStatusRead)
 	assert.NoError(t, err)
 	assert.EqualValues(t, 0, cnt)
@@ -72,35 +73,35 @@ func TestGetNotificationCount(t *testing.T) {
 }
 
 func TestSetNotificationStatus(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	user := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
-	notf := AssertExistsAndLoadBean(t,
+	assert.NoError(t, db.PrepareTestDatabase())
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	notf := db.AssertExistsAndLoadBean(t,
 		&Notification{UserID: user.ID, Status: NotificationStatusRead}).(*Notification)
 	_, err := SetNotificationStatus(notf.ID, user, NotificationStatusPinned)
 	assert.NoError(t, err)
-	AssertExistsAndLoadBean(t,
+	db.AssertExistsAndLoadBean(t,
 		&Notification{ID: notf.ID, Status: NotificationStatusPinned})
 
 	_, err = SetNotificationStatus(1, user, NotificationStatusRead)
 	assert.Error(t, err)
-	_, err = SetNotificationStatus(NonexistentID, user, NotificationStatusRead)
+	_, err = SetNotificationStatus(db.NonexistentID, user, NotificationStatusRead)
 	assert.Error(t, err)
 }
 
 func TestUpdateNotificationStatuses(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	user := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
-	notfUnread := AssertExistsAndLoadBean(t,
+	assert.NoError(t, db.PrepareTestDatabase())
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	notfUnread := db.AssertExistsAndLoadBean(t,
 		&Notification{UserID: user.ID, Status: NotificationStatusUnread}).(*Notification)
-	notfRead := AssertExistsAndLoadBean(t,
+	notfRead := db.AssertExistsAndLoadBean(t,
 		&Notification{UserID: user.ID, Status: NotificationStatusRead}).(*Notification)
-	notfPinned := AssertExistsAndLoadBean(t,
+	notfPinned := db.AssertExistsAndLoadBean(t,
 		&Notification{UserID: user.ID, Status: NotificationStatusPinned}).(*Notification)
 	assert.NoError(t, UpdateNotificationStatuses(user, NotificationStatusUnread, NotificationStatusRead))
-	AssertExistsAndLoadBean(t,
+	db.AssertExistsAndLoadBean(t,
 		&Notification{ID: notfUnread.ID, Status: NotificationStatusRead})
-	AssertExistsAndLoadBean(t,
+	db.AssertExistsAndLoadBean(t,
 		&Notification{ID: notfRead.ID, Status: NotificationStatusRead})
-	AssertExistsAndLoadBean(t,
+	db.AssertExistsAndLoadBean(t,
 		&Notification{ID: notfPinned.ID, Status: NotificationStatusPinned})
 }
diff --git a/models/oauth2.go b/models/oauth2.go
index 127e8d760..ac14813dd 100644
--- a/models/oauth2.go
+++ b/models/oauth2.go
@@ -4,10 +4,12 @@
 
 package models
 
+import "code.gitea.io/gitea/models/db"
+
 // GetActiveOAuth2ProviderLoginSources returns all actived LoginOAuth2 sources
 func GetActiveOAuth2ProviderLoginSources() ([]*LoginSource, error) {
 	sources := make([]*LoginSource, 0, 1)
-	if err := x.Where("is_active = ? and type = ?", true, LoginOAuth2).Find(&sources); err != nil {
+	if err := db.DefaultContext().Engine().Where("is_active = ? and type = ?", true, LoginOAuth2).Find(&sources); err != nil {
 		return nil, err
 	}
 	return sources, nil
@@ -16,7 +18,7 @@ func GetActiveOAuth2ProviderLoginSources() ([]*LoginSource, error) {
 // GetActiveOAuth2LoginSourceByName returns a OAuth2 LoginSource based on the given name
 func GetActiveOAuth2LoginSourceByName(name string) (*LoginSource, error) {
 	loginSource := new(LoginSource)
-	has, err := x.Where("name = ? and type = ? and is_active = ?", name, LoginOAuth2, true).Get(loginSource)
+	has, err := db.DefaultContext().Engine().Where("name = ? and type = ? and is_active = ?", name, LoginOAuth2, true).Get(loginSource)
 	if !has || err != nil {
 		return nil, err
 	}
diff --git a/models/oauth2_application.go b/models/oauth2_application.go
index 93766079d..850b09234 100644
--- a/models/oauth2_application.go
+++ b/models/oauth2_application.go
@@ -11,6 +11,7 @@ import (
 	"net/url"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/secret"
 	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/util"
@@ -37,6 +38,12 @@ type OAuth2Application struct {
 	UpdatedUnix timeutil.TimeStamp `xorm:"INDEX updated"`
 }
 
+func init() {
+	db.RegisterModel(new(OAuth2Application))
+	db.RegisterModel(new(OAuth2AuthorizationCode))
+	db.RegisterModel(new(OAuth2Grant))
+}
+
 // TableName sets the table name to `oauth2_application`
 func (app *OAuth2Application) TableName() string {
 	return "oauth2_application"
@@ -74,7 +81,7 @@ func (app *OAuth2Application) GenerateClientSecret() (string, error) {
 		return "", err
 	}
 	app.ClientSecret = string(hashedSecret)
-	if _, err := x.ID(app.ID).Cols("client_secret").Update(app); err != nil {
+	if _, err := db.DefaultContext().Engine().ID(app.ID).Cols("client_secret").Update(app); err != nil {
 		return "", err
 	}
 	return clientSecret, nil
@@ -87,10 +94,10 @@ func (app *OAuth2Application) ValidateClientSecret(secret []byte) bool {
 
 // GetGrantByUserID returns a OAuth2Grant by its user and application ID
 func (app *OAuth2Application) GetGrantByUserID(userID int64) (*OAuth2Grant, error) {
-	return app.getGrantByUserID(x, userID)
+	return app.getGrantByUserID(db.DefaultContext().Engine(), userID)
 }
 
-func (app *OAuth2Application) getGrantByUserID(e Engine, userID int64) (grant *OAuth2Grant, err error) {
+func (app *OAuth2Application) getGrantByUserID(e db.Engine, userID int64) (grant *OAuth2Grant, err error) {
 	grant = new(OAuth2Grant)
 	if has, err := e.Where("user_id = ? AND application_id = ?", userID, app.ID).Get(grant); err != nil {
 		return nil, err
@@ -102,10 +109,10 @@ func (app *OAuth2Application) getGrantByUserID(e Engine, userID int64) (grant *O
 
 // CreateGrant generates a grant for an user
 func (app *OAuth2Application) CreateGrant(userID int64, scope string) (*OAuth2Grant, error) {
-	return app.createGrant(x, userID, scope)
+	return app.createGrant(db.DefaultContext().Engine(), userID, scope)
 }
 
-func (app *OAuth2Application) createGrant(e Engine, userID int64, scope string) (*OAuth2Grant, error) {
+func (app *OAuth2Application) createGrant(e db.Engine, userID int64, scope string) (*OAuth2Grant, error) {
 	grant := &OAuth2Grant{
 		ApplicationID: app.ID,
 		UserID:        userID,
@@ -120,10 +127,10 @@ func (app *OAuth2Application) createGrant(e Engine, userID int64, scope string)
 
 // GetOAuth2ApplicationByClientID returns the oauth2 application with the given client_id. Returns an error if not found.
 func GetOAuth2ApplicationByClientID(clientID string) (app *OAuth2Application, err error) {
-	return getOAuth2ApplicationByClientID(x, clientID)
+	return getOAuth2ApplicationByClientID(db.DefaultContext().Engine(), clientID)
 }
 
-func getOAuth2ApplicationByClientID(e Engine, clientID string) (app *OAuth2Application, err error) {
+func getOAuth2ApplicationByClientID(e db.Engine, clientID string) (app *OAuth2Application, err error) {
 	app = new(OAuth2Application)
 	has, err := e.Where("client_id = ?", clientID).Get(app)
 	if !has {
@@ -134,10 +141,10 @@ func getOAuth2ApplicationByClientID(e Engine, clientID string) (app *OAuth2Appli
 
 // GetOAuth2ApplicationByID returns the oauth2 application with the given id. Returns an error if not found.
 func GetOAuth2ApplicationByID(id int64) (app *OAuth2Application, err error) {
-	return getOAuth2ApplicationByID(x, id)
+	return getOAuth2ApplicationByID(db.DefaultContext().Engine(), id)
 }
 
-func getOAuth2ApplicationByID(e Engine, id int64) (app *OAuth2Application, err error) {
+func getOAuth2ApplicationByID(e db.Engine, id int64) (app *OAuth2Application, err error) {
 	app = new(OAuth2Application)
 	has, err := e.ID(id).Get(app)
 	if err != nil {
@@ -151,10 +158,10 @@ func getOAuth2ApplicationByID(e Engine, id int64) (app *OAuth2Application, err e
 
 // GetOAuth2ApplicationsByUserID returns all oauth2 applications owned by the user
 func GetOAuth2ApplicationsByUserID(userID int64) (apps []*OAuth2Application, err error) {
-	return getOAuth2ApplicationsByUserID(x, userID)
+	return getOAuth2ApplicationsByUserID(db.DefaultContext().Engine(), userID)
 }
 
-func getOAuth2ApplicationsByUserID(e Engine, userID int64) (apps []*OAuth2Application, err error) {
+func getOAuth2ApplicationsByUserID(e db.Engine, userID int64) (apps []*OAuth2Application, err error) {
 	apps = make([]*OAuth2Application, 0)
 	err = e.Where("uid = ?", userID).Find(&apps)
 	return
@@ -169,10 +176,10 @@ type CreateOAuth2ApplicationOptions struct {
 
 // CreateOAuth2Application inserts a new oauth2 application
 func CreateOAuth2Application(opts CreateOAuth2ApplicationOptions) (*OAuth2Application, error) {
-	return createOAuth2Application(x, opts)
+	return createOAuth2Application(db.DefaultContext().Engine(), opts)
 }
 
-func createOAuth2Application(e Engine, opts CreateOAuth2ApplicationOptions) (*OAuth2Application, error) {
+func createOAuth2Application(e db.Engine, opts CreateOAuth2ApplicationOptions) (*OAuth2Application, error) {
 	clientID := uuid.New().String()
 	app := &OAuth2Application{
 		UID:          opts.UserID,
@@ -196,7 +203,7 @@ type UpdateOAuth2ApplicationOptions struct {
 
 // UpdateOAuth2Application updates an oauth2 application
 func UpdateOAuth2Application(opts UpdateOAuth2ApplicationOptions) (*OAuth2Application, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	if err := sess.Begin(); err != nil {
 		return nil, err
 	}
@@ -221,7 +228,7 @@ func UpdateOAuth2Application(opts UpdateOAuth2ApplicationOptions) (*OAuth2Applic
 	return app, sess.Commit()
 }
 
-func updateOAuth2Application(e Engine, app *OAuth2Application) error {
+func updateOAuth2Application(e db.Engine, app *OAuth2Application) error {
 	if _, err := e.ID(app.ID).Update(app); err != nil {
 		return err
 	}
@@ -257,7 +264,7 @@ func deleteOAuth2Application(sess *xorm.Session, id, userid int64) error {
 
 // DeleteOAuth2Application deletes the application with the given id and the grants and auth codes related to it. It checks if the userid was the creator of the app.
 func DeleteOAuth2Application(id, userid int64) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -270,7 +277,7 @@ func DeleteOAuth2Application(id, userid int64) error {
 
 // ListOAuth2Applications returns a list of oauth2 applications belongs to given user.
 func ListOAuth2Applications(uid int64, listOptions ListOptions) ([]*OAuth2Application, int64, error) {
-	sess := x.
+	sess := db.DefaultContext().Engine().
 		Where("uid=?", uid).
 		Desc("id")
 
@@ -322,10 +329,10 @@ func (code *OAuth2AuthorizationCode) GenerateRedirectURI(state string) (redirect
 
 // Invalidate deletes the auth code from the database to invalidate this code
 func (code *OAuth2AuthorizationCode) Invalidate() error {
-	return code.invalidate(x)
+	return code.invalidate(db.DefaultContext().Engine())
 }
 
-func (code *OAuth2AuthorizationCode) invalidate(e Engine) error {
+func (code *OAuth2AuthorizationCode) invalidate(e db.Engine) error {
 	_, err := e.Delete(code)
 	return err
 }
@@ -354,10 +361,10 @@ func (code *OAuth2AuthorizationCode) validateCodeChallenge(verifier string) bool
 
 // GetOAuth2AuthorizationByCode returns an authorization by its code
 func GetOAuth2AuthorizationByCode(code string) (*OAuth2AuthorizationCode, error) {
-	return getOAuth2AuthorizationByCode(x, code)
+	return getOAuth2AuthorizationByCode(db.DefaultContext().Engine(), code)
 }
 
-func getOAuth2AuthorizationByCode(e Engine, code string) (auth *OAuth2AuthorizationCode, err error) {
+func getOAuth2AuthorizationByCode(e db.Engine, code string) (auth *OAuth2AuthorizationCode, err error) {
 	auth = new(OAuth2AuthorizationCode)
 	if has, err := e.Where("code = ?", code).Get(auth); err != nil {
 		return nil, err
@@ -395,10 +402,10 @@ func (grant *OAuth2Grant) TableName() string {
 
 // GenerateNewAuthorizationCode generates a new authorization code for a grant and saves it to the database
 func (grant *OAuth2Grant) GenerateNewAuthorizationCode(redirectURI, codeChallenge, codeChallengeMethod string) (*OAuth2AuthorizationCode, error) {
-	return grant.generateNewAuthorizationCode(x, redirectURI, codeChallenge, codeChallengeMethod)
+	return grant.generateNewAuthorizationCode(db.DefaultContext().Engine(), redirectURI, codeChallenge, codeChallengeMethod)
 }
 
-func (grant *OAuth2Grant) generateNewAuthorizationCode(e Engine, redirectURI, codeChallenge, codeChallengeMethod string) (code *OAuth2AuthorizationCode, err error) {
+func (grant *OAuth2Grant) generateNewAuthorizationCode(e db.Engine, redirectURI, codeChallenge, codeChallengeMethod string) (code *OAuth2AuthorizationCode, err error) {
 	var codeSecret string
 	if codeSecret, err = secret.New(); err != nil {
 		return &OAuth2AuthorizationCode{}, err
@@ -419,10 +426,10 @@ func (grant *OAuth2Grant) generateNewAuthorizationCode(e Engine, redirectURI, co
 
 // IncreaseCounter increases the counter and updates the grant
 func (grant *OAuth2Grant) IncreaseCounter() error {
-	return grant.increaseCount(x)
+	return grant.increaseCount(db.DefaultContext().Engine())
 }
 
-func (grant *OAuth2Grant) increaseCount(e Engine) error {
+func (grant *OAuth2Grant) increaseCount(e db.Engine) error {
 	_, err := e.ID(grant.ID).Incr("counter").Update(new(OAuth2Grant))
 	if err != nil {
 		return err
@@ -447,10 +454,10 @@ func (grant *OAuth2Grant) ScopeContains(scope string) bool {
 
 // SetNonce updates the current nonce value of a grant
 func (grant *OAuth2Grant) SetNonce(nonce string) error {
-	return grant.setNonce(x, nonce)
+	return grant.setNonce(db.DefaultContext().Engine(), nonce)
 }
 
-func (grant *OAuth2Grant) setNonce(e Engine, nonce string) error {
+func (grant *OAuth2Grant) setNonce(e db.Engine, nonce string) error {
 	grant.Nonce = nonce
 	_, err := e.ID(grant.ID).Cols("nonce").Update(grant)
 	if err != nil {
@@ -461,10 +468,10 @@ func (grant *OAuth2Grant) setNonce(e Engine, nonce string) error {
 
 // GetOAuth2GrantByID returns the grant with the given ID
 func GetOAuth2GrantByID(id int64) (*OAuth2Grant, error) {
-	return getOAuth2GrantByID(x, id)
+	return getOAuth2GrantByID(db.DefaultContext().Engine(), id)
 }
 
-func getOAuth2GrantByID(e Engine, id int64) (grant *OAuth2Grant, err error) {
+func getOAuth2GrantByID(e db.Engine, id int64) (grant *OAuth2Grant, err error) {
 	grant = new(OAuth2Grant)
 	if has, err := e.ID(id).Get(grant); err != nil {
 		return nil, err
@@ -476,10 +483,10 @@ func getOAuth2GrantByID(e Engine, id int64) (grant *OAuth2Grant, err error) {
 
 // GetOAuth2GrantsByUserID lists all grants of a certain user
 func GetOAuth2GrantsByUserID(uid int64) ([]*OAuth2Grant, error) {
-	return getOAuth2GrantsByUserID(x, uid)
+	return getOAuth2GrantsByUserID(db.DefaultContext().Engine(), uid)
 }
 
-func getOAuth2GrantsByUserID(e Engine, uid int64) ([]*OAuth2Grant, error) {
+func getOAuth2GrantsByUserID(e db.Engine, uid int64) ([]*OAuth2Grant, error) {
 	type joinedOAuth2Grant struct {
 		Grant       *OAuth2Grant       `xorm:"extends"`
 		Application *OAuth2Application `xorm:"extends"`
@@ -508,10 +515,10 @@ func getOAuth2GrantsByUserID(e Engine, uid int64) ([]*OAuth2Grant, error) {
 
 // RevokeOAuth2Grant deletes the grant with grantID and userID
 func RevokeOAuth2Grant(grantID, userID int64) error {
-	return revokeOAuth2Grant(x, grantID, userID)
+	return revokeOAuth2Grant(db.DefaultContext().Engine(), grantID, userID)
 }
 
-func revokeOAuth2Grant(e Engine, grantID, userID int64) error {
+func revokeOAuth2Grant(e db.Engine, grantID, userID int64) error {
 	_, err := e.Delete(&OAuth2Grant{ID: grantID, UserID: userID})
 	return err
 }
diff --git a/models/oauth2_application_test.go b/models/oauth2_application_test.go
index 7a4bce85c..b01ef967f 100644
--- a/models/oauth2_application_test.go
+++ b/models/oauth2_application_test.go
@@ -7,23 +7,24 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 //////////////////// Application
 
 func TestOAuth2Application_GenerateClientSecret(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	app := AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1}).(*OAuth2Application)
+	assert.NoError(t, db.PrepareTestDatabase())
+	app := db.AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1}).(*OAuth2Application)
 	secret, err := app.GenerateClientSecret()
 	assert.NoError(t, err)
 	assert.True(t, len(secret) > 0)
-	AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1, ClientSecret: app.ClientSecret})
+	db.AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1, ClientSecret: app.ClientSecret})
 }
 
 func BenchmarkOAuth2Application_GenerateClientSecret(b *testing.B) {
-	assert.NoError(b, PrepareTestDatabase())
-	app := AssertExistsAndLoadBean(b, &OAuth2Application{ID: 1}).(*OAuth2Application)
+	assert.NoError(b, db.PrepareTestDatabase())
+	app := db.AssertExistsAndLoadBean(b, &OAuth2Application{ID: 1}).(*OAuth2Application)
 	for i := 0; i < b.N; i++ {
 		_, _ = app.GenerateClientSecret()
 	}
@@ -40,8 +41,8 @@ func TestOAuth2Application_ContainsRedirectURI(t *testing.T) {
 }
 
 func TestOAuth2Application_ValidateClientSecret(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	app := AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1}).(*OAuth2Application)
+	assert.NoError(t, db.PrepareTestDatabase())
+	app := db.AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1}).(*OAuth2Application)
 	secret, err := app.GenerateClientSecret()
 	assert.NoError(t, err)
 	assert.True(t, app.ValidateClientSecret([]byte(secret)))
@@ -49,7 +50,7 @@ func TestOAuth2Application_ValidateClientSecret(t *testing.T) {
 }
 
 func TestGetOAuth2ApplicationByClientID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	app, err := GetOAuth2ApplicationByClientID("da7da3ba-9a13-4167-856f-3899de0b0138")
 	assert.NoError(t, err)
 	assert.Equal(t, "da7da3ba-9a13-4167-856f-3899de0b0138", app.ClientID)
@@ -60,17 +61,17 @@ func TestGetOAuth2ApplicationByClientID(t *testing.T) {
 }
 
 func TestCreateOAuth2Application(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	app, err := CreateOAuth2Application(CreateOAuth2ApplicationOptions{Name: "newapp", UserID: 1})
 	assert.NoError(t, err)
 	assert.Equal(t, "newapp", app.Name)
 	assert.Len(t, app.ClientID, 36)
-	AssertExistsAndLoadBean(t, &OAuth2Application{Name: "newapp"})
+	db.AssertExistsAndLoadBean(t, &OAuth2Application{Name: "newapp"})
 }
 
 func TestOAuth2Application_LoadUser(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	app := AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1}).(*OAuth2Application)
+	assert.NoError(t, db.PrepareTestDatabase())
+	app := db.AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1}).(*OAuth2Application)
 	assert.NoError(t, app.LoadUser())
 	assert.NotNil(t, app.User)
 }
@@ -80,8 +81,8 @@ func TestOAuth2Application_TableName(t *testing.T) {
 }
 
 func TestOAuth2Application_GetGrantByUserID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	app := AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1}).(*OAuth2Application)
+	assert.NoError(t, db.PrepareTestDatabase())
+	app := db.AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1}).(*OAuth2Application)
 	grant, err := app.GetGrantByUserID(1)
 	assert.NoError(t, err)
 	assert.Equal(t, int64(1), grant.UserID)
@@ -92,8 +93,8 @@ func TestOAuth2Application_GetGrantByUserID(t *testing.T) {
 }
 
 func TestOAuth2Application_CreateGrant(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	app := AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1}).(*OAuth2Application)
+	assert.NoError(t, db.PrepareTestDatabase())
+	app := db.AssertExistsAndLoadBean(t, &OAuth2Application{ID: 1}).(*OAuth2Application)
 	grant, err := app.CreateGrant(2, "")
 	assert.NoError(t, err)
 	assert.NotNil(t, grant)
@@ -105,7 +106,7 @@ func TestOAuth2Application_CreateGrant(t *testing.T) {
 //////////////////// Grant
 
 func TestGetOAuth2GrantByID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	grant, err := GetOAuth2GrantByID(1)
 	assert.NoError(t, err)
 	assert.Equal(t, int64(1), grant.ID)
@@ -116,16 +117,16 @@ func TestGetOAuth2GrantByID(t *testing.T) {
 }
 
 func TestOAuth2Grant_IncreaseCounter(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	grant := AssertExistsAndLoadBean(t, &OAuth2Grant{ID: 1, Counter: 1}).(*OAuth2Grant)
+	assert.NoError(t, db.PrepareTestDatabase())
+	grant := db.AssertExistsAndLoadBean(t, &OAuth2Grant{ID: 1, Counter: 1}).(*OAuth2Grant)
 	assert.NoError(t, grant.IncreaseCounter())
 	assert.Equal(t, int64(2), grant.Counter)
-	AssertExistsAndLoadBean(t, &OAuth2Grant{ID: 1, Counter: 2})
+	db.AssertExistsAndLoadBean(t, &OAuth2Grant{ID: 1, Counter: 2})
 }
 
 func TestOAuth2Grant_ScopeContains(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	grant := AssertExistsAndLoadBean(t, &OAuth2Grant{ID: 1, Scope: "openid profile"}).(*OAuth2Grant)
+	assert.NoError(t, db.PrepareTestDatabase())
+	grant := db.AssertExistsAndLoadBean(t, &OAuth2Grant{ID: 1, Scope: "openid profile"}).(*OAuth2Grant)
 	assert.True(t, grant.ScopeContains("openid"))
 	assert.True(t, grant.ScopeContains("profile"))
 	assert.False(t, grant.ScopeContains("profil"))
@@ -133,8 +134,8 @@ func TestOAuth2Grant_ScopeContains(t *testing.T) {
 }
 
 func TestOAuth2Grant_GenerateNewAuthorizationCode(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	grant := AssertExistsAndLoadBean(t, &OAuth2Grant{ID: 1}).(*OAuth2Grant)
+	assert.NoError(t, db.PrepareTestDatabase())
+	grant := db.AssertExistsAndLoadBean(t, &OAuth2Grant{ID: 1}).(*OAuth2Grant)
 	code, err := grant.GenerateNewAuthorizationCode("https://example2.com/callback", "CjvyTLSdR47G5zYenDA-eDWW4lRrO8yvjcWwbD_deOg", "S256")
 	assert.NoError(t, err)
 	assert.NotNil(t, code)
@@ -146,7 +147,7 @@ func TestOAuth2Grant_TableName(t *testing.T) {
 }
 
 func TestGetOAuth2GrantsByUserID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	result, err := GetOAuth2GrantsByUserID(1)
 	assert.NoError(t, err)
 	assert.Len(t, result, 1)
@@ -159,15 +160,15 @@ func TestGetOAuth2GrantsByUserID(t *testing.T) {
 }
 
 func TestRevokeOAuth2Grant(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	assert.NoError(t, RevokeOAuth2Grant(1, 1))
-	AssertNotExistsBean(t, &OAuth2Grant{ID: 1, UserID: 1})
+	db.AssertNotExistsBean(t, &OAuth2Grant{ID: 1, UserID: 1})
 }
 
 //////////////////// Authorization Code
 
 func TestGetOAuth2AuthorizationByCode(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	code, err := GetOAuth2AuthorizationByCode("authcode")
 	assert.NoError(t, err)
 	assert.NotNil(t, code)
@@ -227,10 +228,10 @@ func TestOAuth2AuthorizationCode_GenerateRedirectURI(t *testing.T) {
 }
 
 func TestOAuth2AuthorizationCode_Invalidate(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	code := AssertExistsAndLoadBean(t, &OAuth2AuthorizationCode{Code: "authcode"}).(*OAuth2AuthorizationCode)
+	assert.NoError(t, db.PrepareTestDatabase())
+	code := db.AssertExistsAndLoadBean(t, &OAuth2AuthorizationCode{Code: "authcode"}).(*OAuth2AuthorizationCode)
 	assert.NoError(t, code.Invalidate())
-	AssertNotExistsBean(t, &OAuth2AuthorizationCode{Code: "authcode"})
+	db.AssertNotExistsBean(t, &OAuth2AuthorizationCode{Code: "authcode"})
 }
 
 func TestOAuth2AuthorizationCode_TableName(t *testing.T) {
diff --git a/models/org.go b/models/org.go
index a3229470a..3b1d9f50e 100644
--- a/models/org.go
+++ b/models/org.go
@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/storage"
@@ -34,25 +35,25 @@ func (org *User) CanCreateOrgRepo(uid int64) (bool, error) {
 	return CanCreateOrgRepo(org.ID, uid)
 }
 
-func (org *User) getTeam(e Engine, name string) (*Team, error) {
+func (org *User) getTeam(e db.Engine, name string) (*Team, error) {
 	return getTeam(e, org.ID, name)
 }
 
 // GetTeam returns named team of organization.
 func (org *User) GetTeam(name string) (*Team, error) {
-	return org.getTeam(x, name)
+	return org.getTeam(db.DefaultContext().Engine(), name)
 }
 
-func (org *User) getOwnerTeam(e Engine) (*Team, error) {
+func (org *User) getOwnerTeam(e db.Engine) (*Team, error) {
 	return org.getTeam(e, ownerTeamName)
 }
 
 // GetOwnerTeam returns owner team of organization.
 func (org *User) GetOwnerTeam() (*Team, error) {
-	return org.getOwnerTeam(x)
+	return org.getOwnerTeam(db.DefaultContext().Engine())
 }
 
-func (org *User) loadTeams(e Engine) error {
+func (org *User) loadTeams(e db.Engine) error {
 	if org.Teams != nil {
 		return nil
 	}
@@ -64,7 +65,7 @@ func (org *User) loadTeams(e Engine) error {
 
 // LoadTeams load teams if not loaded.
 func (org *User) LoadTeams() error {
-	return org.loadTeams(x)
+	return org.loadTeams(db.DefaultContext().Engine())
 }
 
 // GetMembers returns all members of organization.
@@ -84,7 +85,7 @@ type FindOrgMembersOpts struct {
 
 // CountOrgMembers counts the organization's members
 func CountOrgMembers(opts *FindOrgMembersOpts) (int64, error) {
-	sess := x.Where("org_id=?", opts.OrgID)
+	sess := db.DefaultContext().Engine().Where("org_id=?", opts.OrgID)
 	if opts.PublicOnly {
 		sess.And("is_public = ?", true)
 	}
@@ -122,13 +123,13 @@ func (org *User) RemoveMember(uid int64) error {
 	return RemoveOrgUser(org.ID, uid)
 }
 
-func (org *User) removeOrgRepo(e Engine, repoID int64) error {
+func (org *User) removeOrgRepo(e db.Engine, repoID int64) error {
 	return removeOrgRepo(e, org.ID, repoID)
 }
 
 // RemoveOrgRepo removes all team-repository relations of organization.
 func (org *User) RemoveOrgRepo(repoID int64) error {
-	return org.removeOrgRepo(x, repoID)
+	return org.removeOrgRepo(db.DefaultContext().Engine(), repoID)
 }
 
 // CreateOrganization creates record of a new organization.
@@ -161,7 +162,7 @@ func CreateOrganization(org, owner *User) (err error) {
 	org.NumMembers = 1
 	org.Type = UserTypeOrganization
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -237,7 +238,7 @@ func GetOrgByName(name string) (*User, error) {
 		LowerName: strings.ToLower(name),
 		Type:      UserTypeOrganization,
 	}
-	has, err := x.Get(u)
+	has, err := db.DefaultContext().Engine().Get(u)
 	if err != nil {
 		return nil, err
 	} else if !has {
@@ -248,7 +249,7 @@ func GetOrgByName(name string) (*User, error) {
 
 // CountOrganizations returns number of organizations.
 func CountOrganizations() int64 {
-	count, _ := x.
+	count, _ := db.DefaultContext().Engine().
 		Where("type=1").
 		Count(new(User))
 	return count
@@ -260,7 +261,7 @@ func DeleteOrganization(org *User) (err error) {
 		return fmt.Errorf("%s is a user not an organization", org.Name)
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	if err = sess.Begin(); err != nil {
@@ -334,7 +335,11 @@ type OrgUser struct {
 	IsPublic bool  `xorm:"INDEX"`
 }
 
-func isOrganizationOwner(e Engine, orgID, uid int64) (bool, error) {
+func init() {
+	db.RegisterModel(new(OrgUser))
+}
+
+func isOrganizationOwner(e db.Engine, orgID, uid int64) (bool, error) {
 	ownerTeam, err := getOwnerTeam(e, orgID)
 	if err != nil {
 		if IsErrTeamNotExist(err) {
@@ -348,15 +353,15 @@ func isOrganizationOwner(e Engine, orgID, uid int64) (bool, error) {
 
 // IsOrganizationOwner returns true if given user is in the owner team.
 func IsOrganizationOwner(orgID, uid int64) (bool, error) {
-	return isOrganizationOwner(x, orgID, uid)
+	return isOrganizationOwner(db.DefaultContext().Engine(), orgID, uid)
 }
 
 // IsOrganizationMember returns true if given user is member of organization.
 func IsOrganizationMember(orgID, uid int64) (bool, error) {
-	return isOrganizationMember(x, orgID, uid)
+	return isOrganizationMember(db.DefaultContext().Engine(), orgID, uid)
 }
 
-func isOrganizationMember(e Engine, orgID, uid int64) (bool, error) {
+func isOrganizationMember(e db.Engine, orgID, uid int64) (bool, error) {
 	return e.
 		Where("uid=?", uid).
 		And("org_id=?", orgID).
@@ -366,7 +371,7 @@ func isOrganizationMember(e Engine, orgID, uid int64) (bool, error) {
 
 // IsPublicMembership returns true if given user public his/her membership.
 func IsPublicMembership(orgID, uid int64) (bool, error) {
-	return x.
+	return db.DefaultContext().Engine().
 		Where("uid=?", uid).
 		And("org_id=?", orgID).
 		And("is_public=?", true).
@@ -379,7 +384,7 @@ func CanCreateOrgRepo(orgID, uid int64) (bool, error) {
 	if owner, err := IsOrganizationOwner(orgID, uid); owner || err != nil {
 		return owner, err
 	}
-	return x.
+	return db.DefaultContext().Engine().
 		Where(builder.Eq{"team.can_create_org_repo": true}).
 		Join("INNER", "team_user", "team_user.team_id = team.id").
 		And("team_user.uid = ?", uid).
@@ -389,12 +394,12 @@ func CanCreateOrgRepo(orgID, uid int64) (bool, error) {
 
 // GetUsersWhoCanCreateOrgRepo returns users which are able to create repo in organization
 func GetUsersWhoCanCreateOrgRepo(orgID int64) ([]*User, error) {
-	return getUsersWhoCanCreateOrgRepo(x, orgID)
+	return getUsersWhoCanCreateOrgRepo(db.DefaultContext().Engine(), orgID)
 }
 
-func getUsersWhoCanCreateOrgRepo(e Engine, orgID int64) ([]*User, error) {
+func getUsersWhoCanCreateOrgRepo(e db.Engine, orgID int64) ([]*User, error) {
 	users := make([]*User, 0, 10)
-	return users, x.
+	return users, db.DefaultContext().Engine().
 		Join("INNER", "`team_user`", "`team_user`.uid=`user`.id").
 		Join("INNER", "`team`", "`team`.id=`team_user`.team_id").
 		Where(builder.Eq{"team.can_create_org_repo": true}.Or(builder.Eq{"team.authorize": AccessModeOwner})).
@@ -416,7 +421,7 @@ func getOrgsByUserID(sess *xorm.Session, userID int64, showAll bool) ([]*User, e
 // GetOrgsByUserID returns a list of organizations that the given user ID
 // has joined.
 func GetOrgsByUserID(userID int64, showAll bool) ([]*User, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	return getOrgsByUserID(sess, userID, showAll)
 }
@@ -426,10 +431,10 @@ type MinimalOrg = User
 
 // GetUserOrgsList returns one user's all orgs list
 func GetUserOrgsList(user *User) ([]*MinimalOrg, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
-	schema, err := x.TableInfo(new(User))
+	schema, err := db.TableInfo(new(User))
 	if err != nil {
 		return nil, err
 	}
@@ -497,10 +502,10 @@ func getOwnedOrgsByUserID(sess *xorm.Session, userID int64) ([]*User, error) {
 
 // HasOrgOrUserVisible tells if the given user can see the given org or user
 func HasOrgOrUserVisible(org, user *User) bool {
-	return hasOrgOrUserVisible(x, org, user)
+	return hasOrgOrUserVisible(db.DefaultContext().Engine(), org, user)
 }
 
-func hasOrgOrUserVisible(e Engine, orgOrUser, user *User) bool {
+func hasOrgOrUserVisible(e db.Engine, orgOrUser, user *User) bool {
 	// Not SignedUser
 	if user == nil {
 		return orgOrUser.Visibility == structs.VisibleTypePublic
@@ -532,7 +537,7 @@ func HasOrgsVisible(orgs []*User, user *User) bool {
 
 // GetOwnedOrgsByUserID returns a list of organizations are owned by given user ID.
 func GetOwnedOrgsByUserID(userID int64) ([]*User, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	return getOwnedOrgsByUserID(sess, userID)
 }
@@ -540,7 +545,7 @@ func GetOwnedOrgsByUserID(userID int64) ([]*User, error) {
 // GetOwnedOrgsByUserIDDesc returns a list of organizations are owned by
 // given user ID, ordered descending by the given condition.
 func GetOwnedOrgsByUserIDDesc(userID int64, desc string) ([]*User, error) {
-	return getOwnedOrgsByUserID(x.Desc(desc), userID)
+	return getOwnedOrgsByUserID(db.DefaultContext().Engine().Desc(desc), userID)
 }
 
 // GetOrgsCanCreateRepoByUserID returns a list of organizations where given user ID
@@ -548,7 +553,7 @@ func GetOwnedOrgsByUserIDDesc(userID int64, desc string) ([]*User, error) {
 func GetOrgsCanCreateRepoByUserID(userID int64) ([]*User, error) {
 	orgs := make([]*User, 0, 10)
 
-	return orgs, x.Where(builder.In("id", builder.Select("`user`.id").From("`user`").
+	return orgs, db.DefaultContext().Engine().Where(builder.In("id", builder.Select("`user`.id").From("`user`").
 		Join("INNER", "`team_user`", "`team_user`.org_id = `user`.id").
 		Join("INNER", "`team`", "`team`.id = `team_user`.team_id").
 		Where(builder.Eq{"`team_user`.uid": userID}).
@@ -560,7 +565,7 @@ func GetOrgsCanCreateRepoByUserID(userID int64) ([]*User, error) {
 // GetOrgUsersByUserID returns all organization-user relations by user ID.
 func GetOrgUsersByUserID(uid int64, opts *SearchOrganizationsOptions) ([]*OrgUser, error) {
 	ous := make([]*OrgUser, 0, 10)
-	sess := x.
+	sess := db.DefaultContext().Engine().
 		Join("LEFT", "`user`", "`org_user`.org_id=`user`.id").
 		Where("`org_user`.uid=?", uid)
 	if !opts.All {
@@ -580,10 +585,10 @@ func GetOrgUsersByUserID(uid int64, opts *SearchOrganizationsOptions) ([]*OrgUse
 
 // GetOrgUsersByOrgID returns all organization-user relations by organization ID.
 func GetOrgUsersByOrgID(opts *FindOrgMembersOpts) ([]*OrgUser, error) {
-	return getOrgUsersByOrgID(x, opts)
+	return getOrgUsersByOrgID(db.DefaultContext().Engine(), opts)
 }
 
-func getOrgUsersByOrgID(e Engine, opts *FindOrgMembersOpts) ([]*OrgUser, error) {
+func getOrgUsersByOrgID(e db.Engine, opts *FindOrgMembersOpts) ([]*OrgUser, error) {
 	sess := e.Where("org_id=?", opts.OrgID)
 	if opts.PublicOnly {
 		sess.And("is_public = ?", true)
@@ -602,7 +607,7 @@ func getOrgUsersByOrgID(e Engine, opts *FindOrgMembersOpts) ([]*OrgUser, error)
 // ChangeOrgUserStatus changes public or private membership status.
 func ChangeOrgUserStatus(orgID, uid int64, public bool) error {
 	ou := new(OrgUser)
-	has, err := x.
+	has, err := db.DefaultContext().Engine().
 		Where("uid=?", uid).
 		And("org_id=?", orgID).
 		Get(ou)
@@ -613,7 +618,7 @@ func ChangeOrgUserStatus(orgID, uid int64, public bool) error {
 	}
 
 	ou.IsPublic = public
-	_, err = x.ID(ou.ID).Cols("is_public").Update(ou)
+	_, err = db.DefaultContext().Engine().ID(ou.ID).Cols("is_public").Update(ou)
 	return err
 }
 
@@ -624,7 +629,7 @@ func AddOrgUser(orgID, uid int64) error {
 		return err
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -733,7 +738,7 @@ func removeOrgUser(sess *xorm.Session, orgID, userID int64) error {
 
 // RemoveOrgUser removes user from given organization.
 func RemoveOrgUser(orgID, userID int64) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -744,7 +749,7 @@ func RemoveOrgUser(orgID, userID int64) error {
 	return sess.Commit()
 }
 
-func removeOrgRepo(e Engine, orgID, repoID int64) error {
+func removeOrgRepo(e db.Engine, orgID, repoID int64) error {
 	teamRepos := make([]*TeamRepo, 0, 10)
 	if err := e.Find(&teamRepos, &TeamRepo{OrgID: orgID, RepoID: repoID}); err != nil {
 		return err
@@ -770,7 +775,7 @@ func removeOrgRepo(e Engine, orgID, repoID int64) error {
 	return err
 }
 
-func (org *User) getUserTeams(e Engine, userID int64, cols ...string) ([]*Team, error) {
+func (org *User) getUserTeams(e db.Engine, userID int64, cols ...string) ([]*Team, error) {
 	teams := make([]*Team, 0, org.NumTeams)
 	return teams, e.
 		Where("`team_user`.org_id = ?", org.ID).
@@ -782,7 +787,7 @@ func (org *User) getUserTeams(e Engine, userID int64, cols ...string) ([]*Team,
 		Find(&teams)
 }
 
-func (org *User) getUserTeamIDs(e Engine, userID int64) ([]int64, error) {
+func (org *User) getUserTeamIDs(e db.Engine, userID int64) ([]int64, error) {
 	teamIDs := make([]int64, 0, org.NumTeams)
 	return teamIDs, e.
 		Table("team").
@@ -800,13 +805,13 @@ func (org *User) TeamsWithAccessToRepo(repoID int64, mode AccessMode) ([]*Team,
 
 // GetUserTeamIDs returns of all team IDs of the organization that user is member of.
 func (org *User) GetUserTeamIDs(userID int64) ([]int64, error) {
-	return org.getUserTeamIDs(x, userID)
+	return org.getUserTeamIDs(db.DefaultContext().Engine(), userID)
 }
 
 // GetUserTeams returns all teams that belong to user,
 // and that the user has joined.
 func (org *User) GetUserTeams(userID int64) ([]*Team, error) {
-	return org.getUserTeams(x, userID)
+	return org.getUserTeams(db.DefaultContext().Engine(), userID)
 }
 
 // AccessibleReposEnvironment operations involving the repositories that are
@@ -825,7 +830,7 @@ type accessibleReposEnv struct {
 	user    *User
 	team    *Team
 	teamIDs []int64
-	e       Engine
+	e       db.Engine
 	keyword string
 	orderBy SearchOrderBy
 }
@@ -833,10 +838,10 @@ type accessibleReposEnv struct {
 // AccessibleReposEnv builds an AccessibleReposEnvironment for the repositories in `org`
 // that are accessible to the specified user.
 func (org *User) AccessibleReposEnv(userID int64) (AccessibleReposEnvironment, error) {
-	return org.accessibleReposEnv(x, userID)
+	return org.accessibleReposEnv(db.DefaultContext().Engine(), userID)
 }
 
-func (org *User) accessibleReposEnv(e Engine, userID int64) (AccessibleReposEnvironment, error) {
+func (org *User) accessibleReposEnv(e db.Engine, userID int64) (AccessibleReposEnvironment, error) {
 	var user *User
 
 	if userID > 0 {
@@ -866,7 +871,7 @@ func (org *User) AccessibleTeamReposEnv(team *Team) AccessibleReposEnvironment {
 	return &accessibleReposEnv{
 		org:     org,
 		team:    team,
-		e:       x,
+		e:       db.DefaultContext().Engine(),
 		orderBy: SearchOrderByRecentUpdated,
 	}
 }
diff --git a/models/org_team.go b/models/org_team.go
index 7516016a1..280d814ee 100644
--- a/models/org_team.go
+++ b/models/org_team.go
@@ -11,6 +11,7 @@ import (
 	"sort"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 
@@ -37,6 +38,13 @@ type Team struct {
 	CanCreateOrgRepo        bool        `xorm:"NOT NULL DEFAULT false"`
 }
 
+func init() {
+	db.RegisterModel(new(Team))
+	db.RegisterModel(new(TeamUser))
+	db.RegisterModel(new(TeamRepo))
+	db.RegisterModel(new(TeamUnit))
+}
+
 // SearchTeamOptions holds the search options
 type SearchTeamOptions struct {
 	ListOptions
@@ -74,7 +82,7 @@ func SearchTeam(opts *SearchTeamOptions) ([]*Team, int64, error) {
 
 	cond = cond.And(builder.Eq{"org_id": opts.OrgID})
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	count, err := sess.
@@ -112,10 +120,10 @@ func (t *Team) ColorFormat(s fmt.State) {
 
 // GetUnits return a list of available units for a team
 func (t *Team) GetUnits() error {
-	return t.getUnits(x)
+	return t.getUnits(db.DefaultContext().Engine())
 }
 
-func (t *Team) getUnits(e Engine) (err error) {
+func (t *Team) getUnits(e db.Engine) (err error) {
 	if t.Units != nil {
 		return nil
 	}
@@ -152,7 +160,7 @@ func (t *Team) IsMember(userID int64) bool {
 	return isMember
 }
 
-func (t *Team) getRepositories(e Engine) error {
+func (t *Team) getRepositories(e db.Engine) error {
 	if t.Repos != nil {
 		return nil
 	}
@@ -165,13 +173,13 @@ func (t *Team) getRepositories(e Engine) error {
 // GetRepositories returns paginated repositories in team of organization.
 func (t *Team) GetRepositories(opts *SearchTeamOptions) error {
 	if opts.Page == 0 {
-		return t.getRepositories(x)
+		return t.getRepositories(db.DefaultContext().Engine())
 	}
 
 	return t.getRepositories(getPaginatedSession(opts))
 }
 
-func (t *Team) getMembers(e Engine) (err error) {
+func (t *Team) getMembers(e db.Engine) (err error) {
 	t.Members, err = getTeamMembers(e, t.ID)
 	return err
 }
@@ -179,7 +187,7 @@ func (t *Team) getMembers(e Engine) (err error) {
 // GetMembers returns paginated members in team of organization.
 func (t *Team) GetMembers(opts *SearchMembersOptions) (err error) {
 	if opts.Page == 0 {
-		return t.getMembers(x)
+		return t.getMembers(db.DefaultContext().Engine())
 	}
 
 	return t.getMembers(getPaginatedSession(opts))
@@ -196,16 +204,16 @@ func (t *Team) RemoveMember(userID int64) error {
 	return RemoveTeamMember(t, userID)
 }
 
-func (t *Team) hasRepository(e Engine, repoID int64) bool {
+func (t *Team) hasRepository(e db.Engine, repoID int64) bool {
 	return hasTeamRepo(e, t.OrgID, t.ID, repoID)
 }
 
 // HasRepository returns true if given repository belong to team.
 func (t *Team) HasRepository(repoID int64) bool {
-	return t.hasRepository(x, repoID)
+	return t.hasRepository(db.DefaultContext().Engine(), repoID)
 }
 
-func (t *Team) addRepository(e Engine, repo *Repository) (err error) {
+func (t *Team) addRepository(e db.Engine, repo *Repository) (err error) {
 	if err = addTeamRepo(e, t.OrgID, t.ID, repo.ID); err != nil {
 		return err
 	}
@@ -237,7 +245,7 @@ func (t *Team) addRepository(e Engine, repo *Repository) (err error) {
 
 // addAllRepositories adds all repositories to the team.
 // If the team already has some repositories they will be left unchanged.
-func (t *Team) addAllRepositories(e Engine) error {
+func (t *Team) addAllRepositories(e db.Engine) error {
 	var orgRepos []Repository
 	if err := e.Where("owner_id = ?", t.OrgID).Find(&orgRepos); err != nil {
 		return fmt.Errorf("get org repos: %v", err)
@@ -256,7 +264,7 @@ func (t *Team) addAllRepositories(e Engine) error {
 
 // AddAllRepositories adds all repositories to the team
 func (t *Team) AddAllRepositories() (err error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -277,7 +285,7 @@ func (t *Team) AddRepository(repo *Repository) (err error) {
 		return nil
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -296,7 +304,7 @@ func (t *Team) RemoveAllRepositories() (err error) {
 		return nil
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -311,7 +319,7 @@ func (t *Team) RemoveAllRepositories() (err error) {
 
 // removeAllRepositories removes all repositories from team and recalculates access
 // Note: Shall not be called if team includes all repositories
-func (t *Team) removeAllRepositories(e Engine) (err error) {
+func (t *Team) removeAllRepositories(e db.Engine) (err error) {
 	// Delete all accesses.
 	for _, repo := range t.Repos {
 		if err := repo.recalculateTeamAccesses(e, t.ID); err != nil {
@@ -355,7 +363,7 @@ func (t *Team) removeAllRepositories(e Engine) (err error) {
 
 // removeRepository removes a repository from a team and recalculates access
 // Note: Repository shall not be removed from team if it includes all repositories (unless the repository is deleted)
-func (t *Team) removeRepository(e Engine, repo *Repository, recalculate bool) (err error) {
+func (t *Team) removeRepository(e db.Engine, repo *Repository, recalculate bool) (err error) {
 	if err = removeTeamRepo(e, t.ID, repo.ID); err != nil {
 		return err
 	}
@@ -413,7 +421,7 @@ func (t *Team) RemoveRepository(repoID int64) error {
 		return err
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -428,10 +436,10 @@ func (t *Team) RemoveRepository(repoID int64) error {
 
 // UnitEnabled returns if the team has the given unit type enabled
 func (t *Team) UnitEnabled(tp UnitType) bool {
-	return t.unitEnabled(x, tp)
+	return t.unitEnabled(db.DefaultContext().Engine(), tp)
 }
 
-func (t *Team) unitEnabled(e Engine, tp UnitType) bool {
+func (t *Team) unitEnabled(e db.Engine, tp UnitType) bool {
 	if err := t.getUnits(e); err != nil {
 		log.Warn("Error loading team (ID: %d) units: %s", t.ID, err.Error())
 	}
@@ -465,7 +473,7 @@ func NewTeam(t *Team) (err error) {
 		return err
 	}
 
-	has, err := x.ID(t.OrgID).Get(new(User))
+	has, err := db.DefaultContext().Engine().ID(t.OrgID).Get(new(User))
 	if err != nil {
 		return err
 	}
@@ -474,7 +482,7 @@ func NewTeam(t *Team) (err error) {
 	}
 
 	t.LowerName = strings.ToLower(t.Name)
-	has, err = x.
+	has, err = db.DefaultContext().Engine().
 		Where("org_id=?", t.OrgID).
 		And("lower_name=?", t.LowerName).
 		Get(new(Team))
@@ -485,7 +493,7 @@ func NewTeam(t *Team) (err error) {
 		return ErrTeamAlreadyExist{t.OrgID, t.LowerName}
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -532,7 +540,7 @@ func NewTeam(t *Team) (err error) {
 	return sess.Commit()
 }
 
-func getTeam(e Engine, orgID int64, name string) (*Team, error) {
+func getTeam(e db.Engine, orgID int64, name string) (*Team, error) {
 	t := &Team{
 		OrgID:     orgID,
 		LowerName: strings.ToLower(name),
@@ -548,7 +556,7 @@ func getTeam(e Engine, orgID int64, name string) (*Team, error) {
 
 // GetTeam returns team by given team name and organization.
 func GetTeam(orgID int64, name string) (*Team, error) {
-	return getTeam(x, orgID, name)
+	return getTeam(db.DefaultContext().Engine(), orgID, name)
 }
 
 // GetTeamIDsByNames returns a slice of team ids corresponds to names.
@@ -569,11 +577,11 @@ func GetTeamIDsByNames(orgID int64, names []string, ignoreNonExistent bool) ([]i
 }
 
 // getOwnerTeam returns team by given team name and organization.
-func getOwnerTeam(e Engine, orgID int64) (*Team, error) {
+func getOwnerTeam(e db.Engine, orgID int64) (*Team, error) {
 	return getTeam(e, orgID, ownerTeamName)
 }
 
-func getTeamByID(e Engine, teamID int64) (*Team, error) {
+func getTeamByID(e db.Engine, teamID int64) (*Team, error) {
 	t := new(Team)
 	has, err := e.ID(teamID).Get(t)
 	if err != nil {
@@ -586,7 +594,7 @@ func getTeamByID(e Engine, teamID int64) (*Team, error) {
 
 // GetTeamByID returns team by given ID.
 func GetTeamByID(teamID int64) (*Team, error) {
-	return getTeamByID(x, teamID)
+	return getTeamByID(db.DefaultContext().Engine(), teamID)
 }
 
 // GetTeamNamesByID returns team's lower name from a list of team ids.
@@ -596,7 +604,7 @@ func GetTeamNamesByID(teamIDs []int64) ([]string, error) {
 	}
 
 	var teamNames []string
-	err := x.Table("team").
+	err := db.DefaultContext().Engine().Table("team").
 		Select("lower_name").
 		In("id", teamIDs).
 		Asc("name").
@@ -615,7 +623,7 @@ func UpdateTeam(t *Team, authChanged, includeAllChanged bool) (err error) {
 		t.Description = t.Description[:255]
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -689,7 +697,7 @@ func DeleteTeam(t *Team) error {
 		return err
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -745,7 +753,7 @@ type TeamUser struct {
 	UID    int64 `xorm:"UNIQUE(s)"`
 }
 
-func isTeamMember(e Engine, orgID, teamID, userID int64) (bool, error) {
+func isTeamMember(e db.Engine, orgID, teamID, userID int64) (bool, error) {
 	return e.
 		Where("org_id=?", orgID).
 		And("team_id=?", teamID).
@@ -756,17 +764,17 @@ func isTeamMember(e Engine, orgID, teamID, userID int64) (bool, error) {
 
 // IsTeamMember returns true if given user is a member of team.
 func IsTeamMember(orgID, teamID, userID int64) (bool, error) {
-	return isTeamMember(x, orgID, teamID, userID)
+	return isTeamMember(db.DefaultContext().Engine(), orgID, teamID, userID)
 }
 
-func getTeamUsersByTeamID(e Engine, teamID int64) ([]*TeamUser, error) {
+func getTeamUsersByTeamID(e db.Engine, teamID int64) ([]*TeamUser, error) {
 	teamUsers := make([]*TeamUser, 0, 10)
 	return teamUsers, e.
 		Where("team_id=?", teamID).
 		Find(&teamUsers)
 }
 
-func getTeamMembers(e Engine, teamID int64) (_ []*User, err error) {
+func getTeamMembers(e db.Engine, teamID int64) (_ []*User, err error) {
 	teamUsers, err := getTeamUsersByTeamID(e, teamID)
 	if err != nil {
 		return nil, fmt.Errorf("get team-users: %v", err)
@@ -787,10 +795,10 @@ func getTeamMembers(e Engine, teamID int64) (_ []*User, err error) {
 
 // GetTeamMembers returns all members in given team of organization.
 func GetTeamMembers(teamID int64) ([]*User, error) {
-	return getTeamMembers(x, teamID)
+	return getTeamMembers(db.DefaultContext().Engine(), teamID)
 }
 
-func getUserOrgTeams(e Engine, orgID, userID int64) (teams []*Team, err error) {
+func getUserOrgTeams(e db.Engine, orgID, userID int64) (teams []*Team, err error) {
 	return teams, e.
 		Join("INNER", "team_user", "team_user.team_id = team.id").
 		Where("team.org_id = ?", orgID).
@@ -798,7 +806,7 @@ func getUserOrgTeams(e Engine, orgID, userID int64) (teams []*Team, err error) {
 		Find(&teams)
 }
 
-func getUserRepoTeams(e Engine, orgID, userID, repoID int64) (teams []*Team, err error) {
+func getUserRepoTeams(e db.Engine, orgID, userID, repoID int64) (teams []*Team, err error) {
 	return teams, e.
 		Join("INNER", "team_user", "team_user.team_id = team.id").
 		Join("INNER", "team_repo", "team_repo.team_id = team.id").
@@ -810,7 +818,7 @@ func getUserRepoTeams(e Engine, orgID, userID, repoID int64) (teams []*Team, err
 
 // GetUserOrgTeams returns all teams that user belongs to in given organization.
 func GetUserOrgTeams(orgID, userID int64) ([]*Team, error) {
-	return getUserOrgTeams(x, orgID, userID)
+	return getUserOrgTeams(db.DefaultContext().Engine(), orgID, userID)
 }
 
 // AddTeamMember adds new membership of given team to given organization,
@@ -830,7 +838,7 @@ func AddTeamMember(team *Team, userID int64) error {
 		return err
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -925,7 +933,7 @@ func removeTeamMember(e *xorm.Session, team *Team, userID int64) error {
 
 // RemoveTeamMember removes member from given team of given organization.
 func RemoveTeamMember(team *Team, userID int64) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -938,17 +946,17 @@ func RemoveTeamMember(team *Team, userID int64) error {
 
 // IsUserInTeams returns if a user in some teams
 func IsUserInTeams(userID int64, teamIDs []int64) (bool, error) {
-	return isUserInTeams(x, userID, teamIDs)
+	return isUserInTeams(db.DefaultContext().Engine(), userID, teamIDs)
 }
 
-func isUserInTeams(e Engine, userID int64, teamIDs []int64) (bool, error) {
+func isUserInTeams(e db.Engine, userID int64, teamIDs []int64) (bool, error) {
 	return e.Where("uid=?", userID).In("team_id", teamIDs).Exist(new(TeamUser))
 }
 
 // UsersInTeamsCount counts the number of users which are in userIDs and teamIDs
 func UsersInTeamsCount(userIDs, teamIDs []int64) (int64, error) {
 	var ids []int64
-	if err := x.In("uid", userIDs).In("team_id", teamIDs).
+	if err := db.DefaultContext().Engine().In("uid", userIDs).In("team_id", teamIDs).
 		Table("team_user").
 		Cols("uid").GroupBy("uid").Find(&ids); err != nil {
 		return 0, err
@@ -971,7 +979,7 @@ type TeamRepo struct {
 	RepoID int64 `xorm:"UNIQUE(s)"`
 }
 
-func hasTeamRepo(e Engine, orgID, teamID, repoID int64) bool {
+func hasTeamRepo(e db.Engine, orgID, teamID, repoID int64) bool {
 	has, _ := e.
 		Where("org_id=?", orgID).
 		And("team_id=?", teamID).
@@ -982,10 +990,10 @@ func hasTeamRepo(e Engine, orgID, teamID, repoID int64) bool {
 
 // HasTeamRepo returns true if given repository belongs to team.
 func HasTeamRepo(orgID, teamID, repoID int64) bool {
-	return hasTeamRepo(x, orgID, teamID, repoID)
+	return hasTeamRepo(db.DefaultContext().Engine(), orgID, teamID, repoID)
 }
 
-func addTeamRepo(e Engine, orgID, teamID, repoID int64) error {
+func addTeamRepo(e db.Engine, orgID, teamID, repoID int64) error {
 	_, err := e.InsertOne(&TeamRepo{
 		OrgID:  orgID,
 		TeamID: teamID,
@@ -994,7 +1002,7 @@ func addTeamRepo(e Engine, orgID, teamID, repoID int64) error {
 	return err
 }
 
-func removeTeamRepo(e Engine, teamID, repoID int64) error {
+func removeTeamRepo(e db.Engine, teamID, repoID int64) error {
 	_, err := e.Delete(&TeamRepo{
 		TeamID: teamID,
 		RepoID: repoID,
@@ -1005,7 +1013,7 @@ func removeTeamRepo(e Engine, teamID, repoID int64) error {
 // GetTeamsWithAccessToRepo returns all teams in an organization that have given access level to the repository.
 func GetTeamsWithAccessToRepo(orgID, repoID int64, mode AccessMode) ([]*Team, error) {
 	teams := make([]*Team, 0, 5)
-	return teams, x.Where("team.authorize >= ?", mode).
+	return teams, db.DefaultContext().Engine().Where("team.authorize >= ?", mode).
 		Join("INNER", "team_repo", "team_repo.team_id = team.id").
 		And("team_repo.org_id = ?", orgID).
 		And("team_repo.repo_id = ?", repoID).
@@ -1032,13 +1040,13 @@ func (t *TeamUnit) Unit() Unit {
 	return Units[t.Type]
 }
 
-func getUnitsByTeamID(e Engine, teamID int64) (units []*TeamUnit, err error) {
+func getUnitsByTeamID(e db.Engine, teamID int64) (units []*TeamUnit, err error) {
 	return units, e.Where("team_id = ?", teamID).Find(&units)
 }
 
 // UpdateTeamUnits updates a teams's units
 func UpdateTeamUnits(team *Team, units []TeamUnit) (err error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
diff --git a/models/org_team_test.go b/models/org_team_test.go
index 9dc26fd81..f1c8f8887 100644
--- a/models/org_team_test.go
+++ b/models/org_team_test.go
@@ -8,42 +8,43 @@ import (
 	"strings"
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestTeam_IsOwnerTeam(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	team := AssertExistsAndLoadBean(t, &Team{ID: 1}).(*Team)
+	team := db.AssertExistsAndLoadBean(t, &Team{ID: 1}).(*Team)
 	assert.True(t, team.IsOwnerTeam())
 
-	team = AssertExistsAndLoadBean(t, &Team{ID: 2}).(*Team)
+	team = db.AssertExistsAndLoadBean(t, &Team{ID: 2}).(*Team)
 	assert.False(t, team.IsOwnerTeam())
 }
 
 func TestTeam_IsMember(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	team := AssertExistsAndLoadBean(t, &Team{ID: 1}).(*Team)
+	team := db.AssertExistsAndLoadBean(t, &Team{ID: 1}).(*Team)
 	assert.True(t, team.IsMember(2))
 	assert.False(t, team.IsMember(4))
-	assert.False(t, team.IsMember(NonexistentID))
+	assert.False(t, team.IsMember(db.NonexistentID))
 
-	team = AssertExistsAndLoadBean(t, &Team{ID: 2}).(*Team)
+	team = db.AssertExistsAndLoadBean(t, &Team{ID: 2}).(*Team)
 	assert.True(t, team.IsMember(2))
 	assert.True(t, team.IsMember(4))
-	assert.False(t, team.IsMember(NonexistentID))
+	assert.False(t, team.IsMember(db.NonexistentID))
 }
 
 func TestTeam_GetRepositories(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	test := func(teamID int64) {
-		team := AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
+		team := db.AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
 		assert.NoError(t, team.GetRepositories(&SearchTeamOptions{}))
 		assert.Len(t, team.Repos, team.NumRepos)
 		for _, repo := range team.Repos {
-			AssertExistsAndLoadBean(t, &TeamRepo{TeamID: teamID, RepoID: repo.ID})
+			db.AssertExistsAndLoadBean(t, &TeamRepo{TeamID: teamID, RepoID: repo.ID})
 		}
 	}
 	test(1)
@@ -51,14 +52,14 @@ func TestTeam_GetRepositories(t *testing.T) {
 }
 
 func TestTeam_GetMembers(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	test := func(teamID int64) {
-		team := AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
+		team := db.AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
 		assert.NoError(t, team.GetMembers(&SearchMembersOptions{}))
 		assert.Len(t, team.Members, team.NumMembers)
 		for _, member := range team.Members {
-			AssertExistsAndLoadBean(t, &TeamUser{UID: member.ID, TeamID: teamID})
+			db.AssertExistsAndLoadBean(t, &TeamUser{UID: member.ID, TeamID: teamID})
 		}
 	}
 	test(1)
@@ -66,12 +67,12 @@ func TestTeam_GetMembers(t *testing.T) {
 }
 
 func TestTeam_AddMember(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	test := func(teamID, userID int64) {
-		team := AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
+		team := db.AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
 		assert.NoError(t, team.AddMember(userID))
-		AssertExistsAndLoadBean(t, &TeamUser{UID: userID, TeamID: teamID})
+		db.AssertExistsAndLoadBean(t, &TeamUser{UID: userID, TeamID: teamID})
 		CheckConsistencyFor(t, &Team{ID: teamID}, &User{ID: team.OrgID})
 	}
 	test(1, 2)
@@ -80,71 +81,71 @@ func TestTeam_AddMember(t *testing.T) {
 }
 
 func TestTeam_RemoveMember(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	testSuccess := func(teamID, userID int64) {
-		team := AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
+		team := db.AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
 		assert.NoError(t, team.RemoveMember(userID))
-		AssertNotExistsBean(t, &TeamUser{UID: userID, TeamID: teamID})
+		db.AssertNotExistsBean(t, &TeamUser{UID: userID, TeamID: teamID})
 		CheckConsistencyFor(t, &Team{ID: teamID})
 	}
 	testSuccess(1, 4)
 	testSuccess(2, 2)
 	testSuccess(3, 2)
-	testSuccess(3, NonexistentID)
+	testSuccess(3, db.NonexistentID)
 
-	team := AssertExistsAndLoadBean(t, &Team{ID: 1}).(*Team)
+	team := db.AssertExistsAndLoadBean(t, &Team{ID: 1}).(*Team)
 	err := team.RemoveMember(2)
 	assert.True(t, IsErrLastOrgOwner(err))
 }
 
 func TestTeam_HasRepository(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	test := func(teamID, repoID int64, expected bool) {
-		team := AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
+		team := db.AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
 		assert.Equal(t, expected, team.HasRepository(repoID))
 	}
 	test(1, 1, false)
 	test(1, 3, true)
 	test(1, 5, true)
-	test(1, NonexistentID, false)
+	test(1, db.NonexistentID, false)
 
 	test(2, 3, true)
 	test(2, 5, false)
 }
 
 func TestTeam_AddRepository(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	testSuccess := func(teamID, repoID int64) {
-		team := AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
-		repo := AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
+		team := db.AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
+		repo := db.AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
 		assert.NoError(t, team.AddRepository(repo))
-		AssertExistsAndLoadBean(t, &TeamRepo{TeamID: teamID, RepoID: repoID})
+		db.AssertExistsAndLoadBean(t, &TeamRepo{TeamID: teamID, RepoID: repoID})
 		CheckConsistencyFor(t, &Team{ID: teamID}, &Repository{ID: repoID})
 	}
 	testSuccess(2, 3)
 	testSuccess(2, 5)
 
-	team := AssertExistsAndLoadBean(t, &Team{ID: 1}).(*Team)
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	team := db.AssertExistsAndLoadBean(t, &Team{ID: 1}).(*Team)
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
 	assert.Error(t, team.AddRepository(repo))
 	CheckConsistencyFor(t, &Team{ID: 1}, &Repository{ID: 1})
 }
 
 func TestTeam_RemoveRepository(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	testSuccess := func(teamID, repoID int64) {
-		team := AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
+		team := db.AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
 		assert.NoError(t, team.RemoveRepository(repoID))
-		AssertNotExistsBean(t, &TeamRepo{TeamID: teamID, RepoID: repoID})
+		db.AssertNotExistsBean(t, &TeamRepo{TeamID: teamID, RepoID: repoID})
 		CheckConsistencyFor(t, &Team{ID: teamID}, &Repository{ID: repoID})
 	}
 	testSuccess(2, 3)
 	testSuccess(2, 5)
-	testSuccess(1, NonexistentID)
+	testSuccess(1, db.NonexistentID)
 }
 
 func TestIsUsableTeamName(t *testing.T) {
@@ -153,17 +154,17 @@ func TestIsUsableTeamName(t *testing.T) {
 }
 
 func TestNewTeam(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	const teamName = "newTeamName"
 	team := &Team{Name: teamName, OrgID: 3}
 	assert.NoError(t, NewTeam(team))
-	AssertExistsAndLoadBean(t, &Team{Name: teamName})
+	db.AssertExistsAndLoadBean(t, &Team{Name: teamName})
 	CheckConsistencyFor(t, &Team{}, &User{ID: team.OrgID})
 }
 
 func TestGetTeam(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	testSuccess := func(orgID int64, name string) {
 		team, err := GetTeam(orgID, name)
@@ -176,12 +177,12 @@ func TestGetTeam(t *testing.T) {
 
 	_, err := GetTeam(3, "nonexistent")
 	assert.Error(t, err)
-	_, err = GetTeam(NonexistentID, "Owners")
+	_, err = GetTeam(db.NonexistentID, "Owners")
 	assert.Error(t, err)
 }
 
 func TestGetTeamByID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	testSuccess := func(teamID int64) {
 		team, err := GetTeamByID(teamID)
@@ -193,25 +194,25 @@ func TestGetTeamByID(t *testing.T) {
 	testSuccess(3)
 	testSuccess(4)
 
-	_, err := GetTeamByID(NonexistentID)
+	_, err := GetTeamByID(db.NonexistentID)
 	assert.Error(t, err)
 }
 
 func TestUpdateTeam(t *testing.T) {
 	// successful update
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	team := AssertExistsAndLoadBean(t, &Team{ID: 2}).(*Team)
+	team := db.AssertExistsAndLoadBean(t, &Team{ID: 2}).(*Team)
 	team.LowerName = "newname"
 	team.Name = "newName"
 	team.Description = strings.Repeat("A long description!", 100)
 	team.Authorize = AccessModeAdmin
 	assert.NoError(t, UpdateTeam(team, true, false))
 
-	team = AssertExistsAndLoadBean(t, &Team{Name: "newName"}).(*Team)
+	team = db.AssertExistsAndLoadBean(t, &Team{Name: "newName"}).(*Team)
 	assert.True(t, strings.HasPrefix(team.Description, "A long description!"))
 
-	access := AssertExistsAndLoadBean(t, &Access{UserID: 4, RepoID: 3}).(*Access)
+	access := db.AssertExistsAndLoadBean(t, &Access{UserID: 4, RepoID: 3}).(*Access)
 	assert.EqualValues(t, AccessModeAdmin, access.Mode)
 
 	CheckConsistencyFor(t, &Team{ID: team.ID})
@@ -219,9 +220,9 @@ func TestUpdateTeam(t *testing.T) {
 
 func TestUpdateTeam2(t *testing.T) {
 	// update to already-existing team
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	team := AssertExistsAndLoadBean(t, &Team{ID: 2}).(*Team)
+	team := db.AssertExistsAndLoadBean(t, &Team{ID: 2}).(*Team)
 	team.LowerName = "owners"
 	team.Name = "Owners"
 	team.Description = strings.Repeat("A long description!", 100)
@@ -232,24 +233,24 @@ func TestUpdateTeam2(t *testing.T) {
 }
 
 func TestDeleteTeam(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	team := AssertExistsAndLoadBean(t, &Team{ID: 2}).(*Team)
+	team := db.AssertExistsAndLoadBean(t, &Team{ID: 2}).(*Team)
 	assert.NoError(t, DeleteTeam(team))
-	AssertNotExistsBean(t, &Team{ID: team.ID})
-	AssertNotExistsBean(t, &TeamRepo{TeamID: team.ID})
-	AssertNotExistsBean(t, &TeamUser{TeamID: team.ID})
+	db.AssertNotExistsBean(t, &Team{ID: team.ID})
+	db.AssertNotExistsBean(t, &TeamRepo{TeamID: team.ID})
+	db.AssertNotExistsBean(t, &TeamUser{TeamID: team.ID})
 
 	// check that team members don't have "leftover" access to repos
-	user := AssertExistsAndLoadBean(t, &User{ID: 4}).(*User)
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 3}).(*Repository)
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 4}).(*User)
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 3}).(*Repository)
 	accessMode, err := AccessLevel(user, repo)
 	assert.NoError(t, err)
 	assert.True(t, accessMode < AccessModeWrite)
 }
 
 func TestIsTeamMember(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	test := func(orgID, teamID, userID int64, expected bool) {
 		isMember, err := IsTeamMember(orgID, teamID, userID)
 		assert.NoError(t, err)
@@ -258,25 +259,25 @@ func TestIsTeamMember(t *testing.T) {
 
 	test(3, 1, 2, true)
 	test(3, 1, 4, false)
-	test(3, 1, NonexistentID, false)
+	test(3, 1, db.NonexistentID, false)
 
 	test(3, 2, 2, true)
 	test(3, 2, 4, true)
 
-	test(3, NonexistentID, NonexistentID, false)
-	test(NonexistentID, NonexistentID, NonexistentID, false)
+	test(3, db.NonexistentID, db.NonexistentID, false)
+	test(db.NonexistentID, db.NonexistentID, db.NonexistentID, false)
 }
 
 func TestGetTeamMembers(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	test := func(teamID int64) {
-		team := AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
+		team := db.AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
 		members, err := GetTeamMembers(teamID)
 		assert.NoError(t, err)
 		assert.Len(t, members, team.NumMembers)
 		for _, member := range members {
-			AssertExistsAndLoadBean(t, &TeamUser{UID: member.ID, TeamID: teamID})
+			db.AssertExistsAndLoadBean(t, &TeamUser{UID: member.ID, TeamID: teamID})
 		}
 	}
 	test(1)
@@ -284,41 +285,41 @@ func TestGetTeamMembers(t *testing.T) {
 }
 
 func TestGetUserTeams(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	test := func(userID int64) {
 		teams, _, err := SearchTeam(&SearchTeamOptions{UserID: userID})
 		assert.NoError(t, err)
 		for _, team := range teams {
-			AssertExistsAndLoadBean(t, &TeamUser{TeamID: team.ID, UID: userID})
+			db.AssertExistsAndLoadBean(t, &TeamUser{TeamID: team.ID, UID: userID})
 		}
 	}
 	test(2)
 	test(5)
-	test(NonexistentID)
+	test(db.NonexistentID)
 }
 
 func TestGetUserOrgTeams(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	test := func(orgID, userID int64) {
 		teams, err := GetUserOrgTeams(orgID, userID)
 		assert.NoError(t, err)
 		for _, team := range teams {
 			assert.EqualValues(t, orgID, team.OrgID)
-			AssertExistsAndLoadBean(t, &TeamUser{TeamID: team.ID, UID: userID})
+			db.AssertExistsAndLoadBean(t, &TeamUser{TeamID: team.ID, UID: userID})
 		}
 	}
 	test(3, 2)
 	test(3, 4)
-	test(3, NonexistentID)
+	test(3, db.NonexistentID)
 }
 
 func TestAddTeamMember(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	test := func(teamID, userID int64) {
-		team := AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
+		team := db.AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
 		assert.NoError(t, AddTeamMember(team, userID))
-		AssertExistsAndLoadBean(t, &TeamUser{UID: userID, TeamID: teamID})
+		db.AssertExistsAndLoadBean(t, &TeamUser{UID: userID, TeamID: teamID})
 		CheckConsistencyFor(t, &Team{ID: teamID}, &User{ID: team.OrgID})
 	}
 	test(1, 2)
@@ -327,42 +328,42 @@ func TestAddTeamMember(t *testing.T) {
 }
 
 func TestRemoveTeamMember(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	testSuccess := func(teamID, userID int64) {
-		team := AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
+		team := db.AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
 		assert.NoError(t, RemoveTeamMember(team, userID))
-		AssertNotExistsBean(t, &TeamUser{UID: userID, TeamID: teamID})
+		db.AssertNotExistsBean(t, &TeamUser{UID: userID, TeamID: teamID})
 		CheckConsistencyFor(t, &Team{ID: teamID})
 	}
 	testSuccess(1, 4)
 	testSuccess(2, 2)
 	testSuccess(3, 2)
-	testSuccess(3, NonexistentID)
+	testSuccess(3, db.NonexistentID)
 
-	team := AssertExistsAndLoadBean(t, &Team{ID: 1}).(*Team)
+	team := db.AssertExistsAndLoadBean(t, &Team{ID: 1}).(*Team)
 	err := RemoveTeamMember(team, 2)
 	assert.True(t, IsErrLastOrgOwner(err))
 }
 
 func TestHasTeamRepo(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	test := func(teamID, repoID int64, expected bool) {
-		team := AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
+		team := db.AssertExistsAndLoadBean(t, &Team{ID: teamID}).(*Team)
 		assert.Equal(t, expected, HasTeamRepo(team.OrgID, teamID, repoID))
 	}
 	test(1, 1, false)
 	test(1, 3, true)
 	test(1, 5, true)
-	test(1, NonexistentID, false)
+	test(1, db.NonexistentID, false)
 
 	test(2, 3, true)
 	test(2, 5, false)
 }
 
 func TestUsersInTeamsCount(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	test := func(teamIDs, userIDs []int64, expected int64) {
 		count, err := UsersInTeamsCount(teamIDs, userIDs)
diff --git a/models/org_test.go b/models/org_test.go
index 7ba9d8ee8..9990a9d9f 100644
--- a/models/org_test.go
+++ b/models/org_test.go
@@ -7,6 +7,7 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/structs"
 
@@ -14,7 +15,7 @@ import (
 )
 
 func TestUser_IsOwnedBy(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	for _, testCase := range []struct {
 		OrgID         int64
 		UserID        int64
@@ -27,7 +28,7 @@ func TestUser_IsOwnedBy(t *testing.T) {
 		{2, 2, false}, // user2 is not an organization
 		{2, 3, false},
 	} {
-		org := AssertExistsAndLoadBean(t, &User{ID: testCase.OrgID}).(*User)
+		org := db.AssertExistsAndLoadBean(t, &User{ID: testCase.OrgID}).(*User)
 		isOwner, err := org.IsOwnedBy(testCase.UserID)
 		assert.NoError(t, err)
 		assert.Equal(t, testCase.ExpectedOwner, isOwner)
@@ -35,7 +36,7 @@ func TestUser_IsOwnedBy(t *testing.T) {
 }
 
 func TestUser_IsOrgMember(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	for _, testCase := range []struct {
 		OrgID          int64
 		UserID         int64
@@ -48,7 +49,7 @@ func TestUser_IsOrgMember(t *testing.T) {
 		{2, 2, false}, // user2 is not an organization
 		{2, 3, false},
 	} {
-		org := AssertExistsAndLoadBean(t, &User{ID: testCase.OrgID}).(*User)
+		org := db.AssertExistsAndLoadBean(t, &User{ID: testCase.OrgID}).(*User)
 		isMember, err := org.IsOrgMember(testCase.UserID)
 		assert.NoError(t, err)
 		assert.Equal(t, testCase.ExpectedMember, isMember)
@@ -56,8 +57,8 @@ func TestUser_IsOrgMember(t *testing.T) {
 }
 
 func TestUser_GetTeam(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	org := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	org := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 	team, err := org.GetTeam("team1")
 	assert.NoError(t, err)
 	assert.Equal(t, org.ID, team.OrgID)
@@ -66,26 +67,26 @@ func TestUser_GetTeam(t *testing.T) {
 	_, err = org.GetTeam("does not exist")
 	assert.True(t, IsErrTeamNotExist(err))
 
-	nonOrg := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	nonOrg := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	_, err = nonOrg.GetTeam("team")
 	assert.True(t, IsErrTeamNotExist(err))
 }
 
 func TestUser_GetOwnerTeam(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	org := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	org := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 	team, err := org.GetOwnerTeam()
 	assert.NoError(t, err)
 	assert.Equal(t, org.ID, team.OrgID)
 
-	nonOrg := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	nonOrg := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	_, err = nonOrg.GetOwnerTeam()
 	assert.True(t, IsErrTeamNotExist(err))
 }
 
 func TestUser_GetTeams(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	org := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	org := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 	assert.NoError(t, org.LoadTeams())
 	if assert.Len(t, org.Teams, 4) {
 		assert.Equal(t, int64(1), org.Teams[0].ID)
@@ -96,8 +97,8 @@ func TestUser_GetTeams(t *testing.T) {
 }
 
 func TestUser_GetMembers(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	org := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	org := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 	assert.NoError(t, org.GetMembers())
 	if assert.Len(t, org.Members, 3) {
 		assert.Equal(t, int64(2), org.Members[0].ID)
@@ -107,67 +108,67 @@ func TestUser_GetMembers(t *testing.T) {
 }
 
 func TestUser_AddMember(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	org := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	org := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 
 	// add a user that is not a member
-	AssertNotExistsBean(t, &OrgUser{UID: 5, OrgID: 3})
+	db.AssertNotExistsBean(t, &OrgUser{UID: 5, OrgID: 3})
 	prevNumMembers := org.NumMembers
 	assert.NoError(t, org.AddMember(5))
-	AssertExistsAndLoadBean(t, &OrgUser{UID: 5, OrgID: 3})
-	org = AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	db.AssertExistsAndLoadBean(t, &OrgUser{UID: 5, OrgID: 3})
+	org = db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 	assert.Equal(t, prevNumMembers+1, org.NumMembers)
 
 	// add a user that is already a member
-	AssertExistsAndLoadBean(t, &OrgUser{UID: 4, OrgID: 3})
+	db.AssertExistsAndLoadBean(t, &OrgUser{UID: 4, OrgID: 3})
 	prevNumMembers = org.NumMembers
 	assert.NoError(t, org.AddMember(4))
-	AssertExistsAndLoadBean(t, &OrgUser{UID: 4, OrgID: 3})
-	org = AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	db.AssertExistsAndLoadBean(t, &OrgUser{UID: 4, OrgID: 3})
+	org = db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 	assert.Equal(t, prevNumMembers, org.NumMembers)
 
 	CheckConsistencyFor(t, &User{})
 }
 
 func TestUser_RemoveMember(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	org := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	org := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 
 	// remove a user that is a member
-	AssertExistsAndLoadBean(t, &OrgUser{UID: 4, OrgID: 3})
+	db.AssertExistsAndLoadBean(t, &OrgUser{UID: 4, OrgID: 3})
 	prevNumMembers := org.NumMembers
 	assert.NoError(t, org.RemoveMember(4))
-	AssertNotExistsBean(t, &OrgUser{UID: 4, OrgID: 3})
-	org = AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	db.AssertNotExistsBean(t, &OrgUser{UID: 4, OrgID: 3})
+	org = db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 	assert.Equal(t, prevNumMembers-1, org.NumMembers)
 
 	// remove a user that is not a member
-	AssertNotExistsBean(t, &OrgUser{UID: 5, OrgID: 3})
+	db.AssertNotExistsBean(t, &OrgUser{UID: 5, OrgID: 3})
 	prevNumMembers = org.NumMembers
 	assert.NoError(t, org.RemoveMember(5))
-	AssertNotExistsBean(t, &OrgUser{UID: 5, OrgID: 3})
-	org = AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	db.AssertNotExistsBean(t, &OrgUser{UID: 5, OrgID: 3})
+	org = db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 	assert.Equal(t, prevNumMembers, org.NumMembers)
 
 	CheckConsistencyFor(t, &User{}, &Team{})
 }
 
 func TestUser_RemoveOrgRepo(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	org := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
-	repo := AssertExistsAndLoadBean(t, &Repository{OwnerID: org.ID}).(*Repository)
+	assert.NoError(t, db.PrepareTestDatabase())
+	org := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	repo := db.AssertExistsAndLoadBean(t, &Repository{OwnerID: org.ID}).(*Repository)
 
 	// remove a repo that does belong to org
-	AssertExistsAndLoadBean(t, &TeamRepo{RepoID: repo.ID, OrgID: org.ID})
+	db.AssertExistsAndLoadBean(t, &TeamRepo{RepoID: repo.ID, OrgID: org.ID})
 	assert.NoError(t, org.RemoveOrgRepo(repo.ID))
-	AssertNotExistsBean(t, &TeamRepo{RepoID: repo.ID, OrgID: org.ID})
-	AssertExistsAndLoadBean(t, &Repository{ID: repo.ID}) // repo should still exist
+	db.AssertNotExistsBean(t, &TeamRepo{RepoID: repo.ID, OrgID: org.ID})
+	db.AssertExistsAndLoadBean(t, &Repository{ID: repo.ID}) // repo should still exist
 
 	// remove a repo that does not belong to org
 	assert.NoError(t, org.RemoveOrgRepo(repo.ID))
-	AssertNotExistsBean(t, &TeamRepo{RepoID: repo.ID, OrgID: org.ID})
+	db.AssertNotExistsBean(t, &TeamRepo{RepoID: repo.ID, OrgID: org.ID})
 
-	assert.NoError(t, org.RemoveOrgRepo(NonexistentID))
+	assert.NoError(t, org.RemoveOrgRepo(db.NonexistentID))
 
 	CheckConsistencyFor(t,
 		&User{ID: org.ID},
@@ -177,49 +178,49 @@ func TestUser_RemoveOrgRepo(t *testing.T) {
 
 func TestCreateOrganization(t *testing.T) {
 	// successful creation of org
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	owner := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	owner := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	const newOrgName = "neworg"
 	org := &User{
 		Name: newOrgName,
 	}
 
-	AssertNotExistsBean(t, &User{Name: newOrgName, Type: UserTypeOrganization})
+	db.AssertNotExistsBean(t, &User{Name: newOrgName, Type: UserTypeOrganization})
 	assert.NoError(t, CreateOrganization(org, owner))
-	org = AssertExistsAndLoadBean(t,
+	org = db.AssertExistsAndLoadBean(t,
 		&User{Name: newOrgName, Type: UserTypeOrganization}).(*User)
-	ownerTeam := AssertExistsAndLoadBean(t,
+	ownerTeam := db.AssertExistsAndLoadBean(t,
 		&Team{Name: ownerTeamName, OrgID: org.ID}).(*Team)
-	AssertExistsAndLoadBean(t, &TeamUser{UID: owner.ID, TeamID: ownerTeam.ID})
+	db.AssertExistsAndLoadBean(t, &TeamUser{UID: owner.ID, TeamID: ownerTeam.ID})
 	CheckConsistencyFor(t, &User{}, &Team{})
 }
 
 func TestCreateOrganization2(t *testing.T) {
 	// unauthorized creation of org
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	owner := AssertExistsAndLoadBean(t, &User{ID: 5}).(*User)
+	owner := db.AssertExistsAndLoadBean(t, &User{ID: 5}).(*User)
 	const newOrgName = "neworg"
 	org := &User{
 		Name: newOrgName,
 	}
 
-	AssertNotExistsBean(t, &User{Name: newOrgName, Type: UserTypeOrganization})
+	db.AssertNotExistsBean(t, &User{Name: newOrgName, Type: UserTypeOrganization})
 	err := CreateOrganization(org, owner)
 	assert.Error(t, err)
 	assert.True(t, IsErrUserNotAllowedCreateOrg(err))
-	AssertNotExistsBean(t, &User{Name: newOrgName, Type: UserTypeOrganization})
+	db.AssertNotExistsBean(t, &User{Name: newOrgName, Type: UserTypeOrganization})
 	CheckConsistencyFor(t, &User{}, &Team{})
 }
 
 func TestCreateOrganization3(t *testing.T) {
 	// create org with same name as existent org
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	owner := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
-	org := &User{Name: "user3"}                       // should already exist
-	AssertExistsAndLoadBean(t, &User{Name: org.Name}) // sanity check
+	owner := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	org := &User{Name: "user3"}                          // should already exist
+	db.AssertExistsAndLoadBean(t, &User{Name: org.Name}) // sanity check
 	err := CreateOrganization(org, owner)
 	assert.Error(t, err)
 	assert.True(t, IsErrUserAlreadyExist(err))
@@ -228,9 +229,9 @@ func TestCreateOrganization3(t *testing.T) {
 
 func TestCreateOrganization4(t *testing.T) {
 	// create org with unusable name
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	owner := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	owner := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	err := CreateOrganization(&User{Name: "assets"}, owner)
 	assert.Error(t, err)
 	assert.True(t, IsErrNameReserved(err))
@@ -238,7 +239,7 @@ func TestCreateOrganization4(t *testing.T) {
 }
 
 func TestGetOrgByName(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	org, err := GetOrgByName("user3")
 	assert.NoError(t, err)
@@ -253,32 +254,32 @@ func TestGetOrgByName(t *testing.T) {
 }
 
 func TestCountOrganizations(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	expected, err := x.Where("type=?", UserTypeOrganization).Count(&User{})
+	assert.NoError(t, db.PrepareTestDatabase())
+	expected, err := db.DefaultContext().Engine().Where("type=?", UserTypeOrganization).Count(&User{})
 	assert.NoError(t, err)
 	assert.Equal(t, expected, CountOrganizations())
 }
 
 func TestDeleteOrganization(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	org := AssertExistsAndLoadBean(t, &User{ID: 6}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	org := db.AssertExistsAndLoadBean(t, &User{ID: 6}).(*User)
 	assert.NoError(t, DeleteOrganization(org))
-	AssertNotExistsBean(t, &User{ID: 6})
-	AssertNotExistsBean(t, &OrgUser{OrgID: 6})
-	AssertNotExistsBean(t, &Team{OrgID: 6})
+	db.AssertNotExistsBean(t, &User{ID: 6})
+	db.AssertNotExistsBean(t, &OrgUser{OrgID: 6})
+	db.AssertNotExistsBean(t, &Team{OrgID: 6})
 
-	org = AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	org = db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 	err := DeleteOrganization(org)
 	assert.Error(t, err)
 	assert.True(t, IsErrUserOwnRepos(err))
 
-	user := AssertExistsAndLoadBean(t, &User{ID: 5}).(*User)
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 5}).(*User)
 	assert.Error(t, DeleteOrganization(user))
 	CheckConsistencyFor(t, &User{}, &Team{})
 }
 
 func TestIsOrganizationOwner(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	test := func(orgID, userID int64, expected bool) {
 		isOwner, err := IsOrganizationOwner(orgID, userID)
 		assert.NoError(t, err)
@@ -288,11 +289,11 @@ func TestIsOrganizationOwner(t *testing.T) {
 	test(3, 3, false)
 	test(6, 5, true)
 	test(6, 4, false)
-	test(NonexistentID, NonexistentID, false)
+	test(db.NonexistentID, db.NonexistentID, false)
 }
 
 func TestIsOrganizationMember(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	test := func(orgID, userID int64, expected bool) {
 		isMember, err := IsOrganizationMember(orgID, userID)
 		assert.NoError(t, err)
@@ -303,11 +304,11 @@ func TestIsOrganizationMember(t *testing.T) {
 	test(3, 4, true)
 	test(6, 5, true)
 	test(6, 4, false)
-	test(NonexistentID, NonexistentID, false)
+	test(db.NonexistentID, db.NonexistentID, false)
 }
 
 func TestIsPublicMembership(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	test := func(orgID, userID int64, expected bool) {
 		isMember, err := IsPublicMembership(orgID, userID)
 		assert.NoError(t, err)
@@ -318,11 +319,11 @@ func TestIsPublicMembership(t *testing.T) {
 	test(3, 4, false)
 	test(6, 5, true)
 	test(6, 4, false)
-	test(NonexistentID, NonexistentID, false)
+	test(db.NonexistentID, db.NonexistentID, false)
 }
 
 func TestGetOrgsByUserID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	orgs, err := GetOrgsByUserID(4, true)
 	assert.NoError(t, err)
@@ -336,7 +337,7 @@ func TestGetOrgsByUserID(t *testing.T) {
 }
 
 func TestGetOwnedOrgsByUserID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	orgs, err := GetOwnedOrgsByUserID(2)
 	assert.NoError(t, err)
@@ -350,7 +351,7 @@ func TestGetOwnedOrgsByUserID(t *testing.T) {
 }
 
 func TestGetOwnedOrgsByUserIDDesc(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	orgs, err := GetOwnedOrgsByUserIDDesc(5, "id")
 	assert.NoError(t, err)
@@ -365,7 +366,7 @@ func TestGetOwnedOrgsByUserIDDesc(t *testing.T) {
 }
 
 func TestGetOrgUsersByUserID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	orgUsers, err := GetOrgUsersByUserID(5, &SearchOrganizationsOptions{All: true})
 	assert.NoError(t, err)
@@ -395,7 +396,7 @@ func TestGetOrgUsersByUserID(t *testing.T) {
 }
 
 func TestGetOrgUsersByOrgID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	orgUsers, err := GetOrgUsersByOrgID(&FindOrgMembersOpts{
 		ListOptions: ListOptions{},
@@ -420,7 +421,7 @@ func TestGetOrgUsersByOrgID(t *testing.T) {
 
 	orgUsers, err = GetOrgUsersByOrgID(&FindOrgMembersOpts{
 		ListOptions: ListOptions{},
-		OrgID:       NonexistentID,
+		OrgID:       db.NonexistentID,
 		PublicOnly:  false,
 	})
 	assert.NoError(t, err)
@@ -428,33 +429,33 @@ func TestGetOrgUsersByOrgID(t *testing.T) {
 }
 
 func TestChangeOrgUserStatus(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	testSuccess := func(orgID, userID int64, public bool) {
 		assert.NoError(t, ChangeOrgUserStatus(orgID, userID, public))
-		orgUser := AssertExistsAndLoadBean(t, &OrgUser{OrgID: orgID, UID: userID}).(*OrgUser)
+		orgUser := db.AssertExistsAndLoadBean(t, &OrgUser{OrgID: orgID, UID: userID}).(*OrgUser)
 		assert.Equal(t, public, orgUser.IsPublic)
 	}
 
 	testSuccess(3, 2, false)
 	testSuccess(3, 2, false)
 	testSuccess(3, 4, true)
-	assert.NoError(t, ChangeOrgUserStatus(NonexistentID, NonexistentID, true))
+	assert.NoError(t, ChangeOrgUserStatus(db.NonexistentID, db.NonexistentID, true))
 }
 
 func TestAddOrgUser(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	testSuccess := func(orgID, userID int64, isPublic bool) {
-		org := AssertExistsAndLoadBean(t, &User{ID: orgID}).(*User)
+		org := db.AssertExistsAndLoadBean(t, &User{ID: orgID}).(*User)
 		expectedNumMembers := org.NumMembers
-		if !BeanExists(t, &OrgUser{OrgID: orgID, UID: userID}) {
+		if !db.BeanExists(t, &OrgUser{OrgID: orgID, UID: userID}) {
 			expectedNumMembers++
 		}
 		assert.NoError(t, AddOrgUser(orgID, userID))
 		ou := &OrgUser{OrgID: orgID, UID: userID}
-		AssertExistsAndLoadBean(t, ou)
+		db.AssertExistsAndLoadBean(t, ou)
 		assert.Equal(t, isPublic, ou.IsPublic)
-		org = AssertExistsAndLoadBean(t, &User{ID: orgID}).(*User)
+		org = db.AssertExistsAndLoadBean(t, &User{ID: orgID}).(*User)
 		assert.EqualValues(t, expectedNumMembers, org.NumMembers)
 	}
 
@@ -470,16 +471,16 @@ func TestAddOrgUser(t *testing.T) {
 }
 
 func TestRemoveOrgUser(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	testSuccess := func(orgID, userID int64) {
-		org := AssertExistsAndLoadBean(t, &User{ID: orgID}).(*User)
+		org := db.AssertExistsAndLoadBean(t, &User{ID: orgID}).(*User)
 		expectedNumMembers := org.NumMembers
-		if BeanExists(t, &OrgUser{OrgID: orgID, UID: userID}) {
+		if db.BeanExists(t, &OrgUser{OrgID: orgID, UID: userID}) {
 			expectedNumMembers--
 		}
 		assert.NoError(t, RemoveOrgUser(orgID, userID))
-		AssertNotExistsBean(t, &OrgUser{OrgID: orgID, UID: userID})
-		org = AssertExistsAndLoadBean(t, &User{ID: orgID}).(*User)
+		db.AssertNotExistsBean(t, &OrgUser{OrgID: orgID, UID: userID})
+		org = db.AssertExistsAndLoadBean(t, &User{ID: orgID}).(*User)
 		assert.EqualValues(t, expectedNumMembers, org.NumMembers)
 	}
 	testSuccess(3, 4)
@@ -488,13 +489,13 @@ func TestRemoveOrgUser(t *testing.T) {
 	err := RemoveOrgUser(7, 5)
 	assert.Error(t, err)
 	assert.True(t, IsErrLastOrgOwner(err))
-	AssertExistsAndLoadBean(t, &OrgUser{OrgID: 7, UID: 5})
+	db.AssertExistsAndLoadBean(t, &OrgUser{OrgID: 7, UID: 5})
 	CheckConsistencyFor(t, &User{}, &Team{})
 }
 
 func TestUser_GetUserTeamIDs(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	org := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	org := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 	testSuccess := func(userID int64, expected []int64) {
 		teamIDs, err := org.GetUserTeamIDs(userID)
 		assert.NoError(t, err)
@@ -502,12 +503,12 @@ func TestUser_GetUserTeamIDs(t *testing.T) {
 	}
 	testSuccess(2, []int64{1, 2})
 	testSuccess(4, []int64{2})
-	testSuccess(NonexistentID, []int64{})
+	testSuccess(db.NonexistentID, []int64{})
 }
 
 func TestAccessibleReposEnv_CountRepos(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	org := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	org := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 	testSuccess := func(userID, expectedCount int64) {
 		env, err := org.AccessibleReposEnv(userID)
 		assert.NoError(t, err)
@@ -520,8 +521,8 @@ func TestAccessibleReposEnv_CountRepos(t *testing.T) {
 }
 
 func TestAccessibleReposEnv_RepoIDs(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	org := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	org := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 	testSuccess := func(userID, _, pageSize int64, expectedRepoIDs []int64) {
 		env, err := org.AccessibleReposEnv(userID)
 		assert.NoError(t, err)
@@ -534,8 +535,8 @@ func TestAccessibleReposEnv_RepoIDs(t *testing.T) {
 }
 
 func TestAccessibleReposEnv_Repos(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	org := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	org := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 	testSuccess := func(userID int64, expectedRepoIDs []int64) {
 		env, err := org.AccessibleReposEnv(userID)
 		assert.NoError(t, err)
@@ -543,7 +544,7 @@ func TestAccessibleReposEnv_Repos(t *testing.T) {
 		assert.NoError(t, err)
 		expectedRepos := make([]*Repository, len(expectedRepoIDs))
 		for i, repoID := range expectedRepoIDs {
-			expectedRepos[i] = AssertExistsAndLoadBean(t,
+			expectedRepos[i] = db.AssertExistsAndLoadBean(t,
 				&Repository{ID: repoID}).(*Repository)
 		}
 		assert.Equal(t, expectedRepos, repos)
@@ -553,8 +554,8 @@ func TestAccessibleReposEnv_Repos(t *testing.T) {
 }
 
 func TestAccessibleReposEnv_MirrorRepos(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	org := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	org := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 	testSuccess := func(userID int64, expectedRepoIDs []int64) {
 		env, err := org.AccessibleReposEnv(userID)
 		assert.NoError(t, err)
@@ -562,7 +563,7 @@ func TestAccessibleReposEnv_MirrorRepos(t *testing.T) {
 		assert.NoError(t, err)
 		expectedRepos := make([]*Repository, len(expectedRepoIDs))
 		for i, repoID := range expectedRepoIDs {
-			expectedRepos[i] = AssertExistsAndLoadBean(t,
+			expectedRepos[i] = db.AssertExistsAndLoadBean(t,
 				&Repository{ID: repoID}).(*Repository)
 		}
 		assert.Equal(t, expectedRepos, repos)
@@ -572,9 +573,9 @@ func TestAccessibleReposEnv_MirrorRepos(t *testing.T) {
 }
 
 func TestHasOrgVisibleTypePublic(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	owner := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
-	user3 := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	owner := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user3 := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 
 	const newOrgName = "test-org-public"
 	org := &User{
@@ -582,9 +583,9 @@ func TestHasOrgVisibleTypePublic(t *testing.T) {
 		Visibility: structs.VisibleTypePublic,
 	}
 
-	AssertNotExistsBean(t, &User{Name: org.Name, Type: UserTypeOrganization})
+	db.AssertNotExistsBean(t, &User{Name: org.Name, Type: UserTypeOrganization})
 	assert.NoError(t, CreateOrganization(org, owner))
-	org = AssertExistsAndLoadBean(t,
+	org = db.AssertExistsAndLoadBean(t,
 		&User{Name: org.Name, Type: UserTypeOrganization}).(*User)
 	test1 := HasOrgOrUserVisible(org, owner)
 	test2 := HasOrgOrUserVisible(org, user3)
@@ -595,9 +596,9 @@ func TestHasOrgVisibleTypePublic(t *testing.T) {
 }
 
 func TestHasOrgVisibleTypeLimited(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	owner := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
-	user3 := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	owner := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user3 := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 
 	const newOrgName = "test-org-limited"
 	org := &User{
@@ -605,9 +606,9 @@ func TestHasOrgVisibleTypeLimited(t *testing.T) {
 		Visibility: structs.VisibleTypeLimited,
 	}
 
-	AssertNotExistsBean(t, &User{Name: org.Name, Type: UserTypeOrganization})
+	db.AssertNotExistsBean(t, &User{Name: org.Name, Type: UserTypeOrganization})
 	assert.NoError(t, CreateOrganization(org, owner))
-	org = AssertExistsAndLoadBean(t,
+	org = db.AssertExistsAndLoadBean(t,
 		&User{Name: org.Name, Type: UserTypeOrganization}).(*User)
 	test1 := HasOrgOrUserVisible(org, owner)
 	test2 := HasOrgOrUserVisible(org, user3)
@@ -618,9 +619,9 @@ func TestHasOrgVisibleTypeLimited(t *testing.T) {
 }
 
 func TestHasOrgVisibleTypePrivate(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	owner := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
-	user3 := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	owner := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user3 := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 
 	const newOrgName = "test-org-private"
 	org := &User{
@@ -628,9 +629,9 @@ func TestHasOrgVisibleTypePrivate(t *testing.T) {
 		Visibility: structs.VisibleTypePrivate,
 	}
 
-	AssertNotExistsBean(t, &User{Name: org.Name, Type: UserTypeOrganization})
+	db.AssertNotExistsBean(t, &User{Name: org.Name, Type: UserTypeOrganization})
 	assert.NoError(t, CreateOrganization(org, owner))
-	org = AssertExistsAndLoadBean(t,
+	org = db.AssertExistsAndLoadBean(t,
 		&User{Name: org.Name, Type: UserTypeOrganization}).(*User)
 	test1 := HasOrgOrUserVisible(org, owner)
 	test2 := HasOrgOrUserVisible(org, user3)
@@ -641,7 +642,7 @@ func TestHasOrgVisibleTypePrivate(t *testing.T) {
 }
 
 func TestGetUsersWhoCanCreateOrgRepo(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	users, err := GetUsersWhoCanCreateOrgRepo(3)
 	assert.NoError(t, err)
diff --git a/models/project.go b/models/project.go
index 7c976711b..1e520b877 100644
--- a/models/project.go
+++ b/models/project.go
@@ -8,6 +8,7 @@ import (
 	"errors"
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/util"
@@ -55,6 +56,10 @@ type Project struct {
 	ClosedDateUnix timeutil.TimeStamp
 }
 
+func init() {
+	db.RegisterModel(new(Project))
+}
+
 // GetProjectsConfig retrieves the types of configurations projects could have
 func GetProjectsConfig() []ProjectsConfig {
 	return []ProjectsConfig{
@@ -85,10 +90,10 @@ type ProjectSearchOptions struct {
 
 // GetProjects returns a list of all projects that have been created in the repository
 func GetProjects(opts ProjectSearchOptions) ([]*Project, int64, error) {
-	return getProjects(x, opts)
+	return getProjects(db.DefaultContext().Engine(), opts)
 }
 
-func getProjects(e Engine, opts ProjectSearchOptions) ([]*Project, int64, error) {
+func getProjects(e db.Engine, opts ProjectSearchOptions) ([]*Project, int64, error) {
 	projects := make([]*Project, 0, setting.UI.IssuePagingNum)
 
 	var cond builder.Cond = builder.Eq{"repo_id": opts.RepoID}
@@ -138,7 +143,7 @@ func NewProject(p *Project) error {
 		return errors.New("project type is not valid")
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	if err := sess.Begin(); err != nil {
@@ -162,10 +167,10 @@ func NewProject(p *Project) error {
 
 // GetProjectByID returns the projects in a repository
 func GetProjectByID(id int64) (*Project, error) {
-	return getProjectByID(x, id)
+	return getProjectByID(db.DefaultContext().Engine(), id)
 }
 
-func getProjectByID(e Engine, id int64) (*Project, error) {
+func getProjectByID(e db.Engine, id int64) (*Project, error) {
 	p := new(Project)
 
 	has, err := e.ID(id).Get(p)
@@ -180,10 +185,10 @@ func getProjectByID(e Engine, id int64) (*Project, error) {
 
 // UpdateProject updates project properties
 func UpdateProject(p *Project) error {
-	return updateProject(x, p)
+	return updateProject(db.DefaultContext().Engine(), p)
 }
 
-func updateProject(e Engine, p *Project) error {
+func updateProject(e db.Engine, p *Project) error {
 	_, err := e.ID(p.ID).Cols(
 		"title",
 		"description",
@@ -191,7 +196,7 @@ func updateProject(e Engine, p *Project) error {
 	return err
 }
 
-func updateRepositoryProjectCount(e Engine, repoID int64) error {
+func updateRepositoryProjectCount(e db.Engine, repoID int64) error {
 	if _, err := e.Exec(builder.Update(
 		builder.Eq{
 			"`num_projects`": builder.Select("count(*)").From("`project`").
@@ -215,7 +220,7 @@ func updateRepositoryProjectCount(e Engine, repoID int64) error {
 
 // ChangeProjectStatusByRepoIDAndID toggles a project between opened and closed
 func ChangeProjectStatusByRepoIDAndID(repoID, projectID int64, isClosed bool) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -239,7 +244,7 @@ func ChangeProjectStatusByRepoIDAndID(repoID, projectID int64, isClosed bool) er
 
 // ChangeProjectStatus toggle a project between opened and closed
 func ChangeProjectStatus(p *Project, isClosed bool) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -252,7 +257,7 @@ func ChangeProjectStatus(p *Project, isClosed bool) error {
 	return sess.Commit()
 }
 
-func changeProjectStatus(e Engine, p *Project, isClosed bool) error {
+func changeProjectStatus(e db.Engine, p *Project, isClosed bool) error {
 	p.IsClosed = isClosed
 	p.ClosedDateUnix = timeutil.TimeStampNow()
 	count, err := e.ID(p.ID).Where("repo_id = ? AND is_closed = ?", p.RepoID, !isClosed).Cols("is_closed", "closed_date_unix").Update(p)
@@ -268,7 +273,7 @@ func changeProjectStatus(e Engine, p *Project, isClosed bool) error {
 
 // DeleteProjectByID deletes a project from a repository.
 func DeleteProjectByID(id int64) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -281,7 +286,7 @@ func DeleteProjectByID(id int64) error {
 	return sess.Commit()
 }
 
-func deleteProjectByID(e Engine, id int64) error {
+func deleteProjectByID(e db.Engine, id int64) error {
 	p, err := getProjectByID(e, id)
 	if err != nil {
 		if IsErrProjectNotExist(err) {
diff --git a/models/project_board.go b/models/project_board.go
index 4b313ed8f..901850e51 100644
--- a/models/project_board.go
+++ b/models/project_board.go
@@ -5,6 +5,7 @@
 package models
 
 import (
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/timeutil"
 
@@ -47,6 +48,10 @@ type ProjectBoard struct {
 	Issues []*Issue `xorm:"-"`
 }
 
+func init() {
+	db.RegisterModel(new(ProjectBoard))
+}
+
 // IsProjectBoardTypeValid checks if the project board type is valid
 func IsProjectBoardTypeValid(p ProjectBoardType) bool {
 	switch p {
@@ -95,13 +100,13 @@ func createBoardsForProjectsType(sess *xorm.Session, project *Project) error {
 
 // NewProjectBoard adds a new project board to a given project
 func NewProjectBoard(board *ProjectBoard) error {
-	_, err := x.Insert(board)
+	_, err := db.DefaultContext().Engine().Insert(board)
 	return err
 }
 
 // DeleteProjectBoardByID removes all issues references to the project board.
 func DeleteProjectBoardByID(boardID int64) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -114,7 +119,7 @@ func DeleteProjectBoardByID(boardID int64) error {
 	return sess.Commit()
 }
 
-func deleteProjectBoardByID(e Engine, boardID int64) error {
+func deleteProjectBoardByID(e db.Engine, boardID int64) error {
 	board, err := getProjectBoard(e, boardID)
 	if err != nil {
 		if IsErrProjectBoardNotExist(err) {
@@ -134,17 +139,17 @@ func deleteProjectBoardByID(e Engine, boardID int64) error {
 	return nil
 }
 
-func deleteProjectBoardByProjectID(e Engine, projectID int64) error {
+func deleteProjectBoardByProjectID(e db.Engine, projectID int64) error {
 	_, err := e.Where("project_id=?", projectID).Delete(&ProjectBoard{})
 	return err
 }
 
 // GetProjectBoard fetches the current board of a project
 func GetProjectBoard(boardID int64) (*ProjectBoard, error) {
-	return getProjectBoard(x, boardID)
+	return getProjectBoard(db.DefaultContext().Engine(), boardID)
 }
 
-func getProjectBoard(e Engine, boardID int64) (*ProjectBoard, error) {
+func getProjectBoard(e db.Engine, boardID int64) (*ProjectBoard, error) {
 	board := new(ProjectBoard)
 
 	has, err := e.ID(boardID).Get(board)
@@ -159,10 +164,10 @@ func getProjectBoard(e Engine, boardID int64) (*ProjectBoard, error) {
 
 // UpdateProjectBoard updates a project board
 func UpdateProjectBoard(board *ProjectBoard) error {
-	return updateProjectBoard(x, board)
+	return updateProjectBoard(db.DefaultContext().Engine(), board)
 }
 
-func updateProjectBoard(e Engine, board *ProjectBoard) error {
+func updateProjectBoard(e db.Engine, board *ProjectBoard) error {
 	var fieldToUpdate []string
 
 	if board.Sorting != 0 {
@@ -181,10 +186,10 @@ func updateProjectBoard(e Engine, board *ProjectBoard) error {
 // GetProjectBoards fetches all boards related to a project
 // if no default board set, first board is a temporary "Uncategorized" board
 func GetProjectBoards(projectID int64) (ProjectBoardList, error) {
-	return getProjectBoards(x, projectID)
+	return getProjectBoards(db.DefaultContext().Engine(), projectID)
 }
 
-func getProjectBoards(e Engine, projectID int64) ([]*ProjectBoard, error) {
+func getProjectBoards(e db.Engine, projectID int64) ([]*ProjectBoard, error) {
 	boards := make([]*ProjectBoard, 0, 5)
 
 	if err := e.Where("project_id=? AND `default`=?", projectID, false).OrderBy("Sorting").Find(&boards); err != nil {
@@ -200,7 +205,7 @@ func getProjectBoards(e Engine, projectID int64) ([]*ProjectBoard, error) {
 }
 
 // getDefaultBoard return default board and create a dummy if none exist
-func getDefaultBoard(e Engine, projectID int64) (*ProjectBoard, error) {
+func getDefaultBoard(e db.Engine, projectID int64) (*ProjectBoard, error) {
 	var board ProjectBoard
 	exist, err := e.Where("project_id=? AND `default`=?", projectID, true).Get(&board)
 	if err != nil {
@@ -221,9 +226,7 @@ func getDefaultBoard(e Engine, projectID int64) (*ProjectBoard, error) {
 // SetDefaultBoard represents a board for issues not assigned to one
 // if boardID is 0 unset default
 func SetDefaultBoard(projectID, boardID int64) error {
-	sess := x
-
-	_, err := sess.Where(builder.Eq{
+	_, err := db.DefaultContext().Engine().Where(builder.Eq{
 		"project_id": projectID,
 		"`default`":  true,
 	}).Cols("`default`").Update(&ProjectBoard{Default: false})
@@ -232,7 +235,7 @@ func SetDefaultBoard(projectID, boardID int64) error {
 	}
 
 	if boardID > 0 {
-		_, err = sess.ID(boardID).Where(builder.Eq{"project_id": projectID}).
+		_, err = db.DefaultContext().Engine().ID(boardID).Where(builder.Eq{"project_id": projectID}).
 			Cols("`default`").Update(&ProjectBoard{Default: true})
 	}
 
@@ -290,7 +293,7 @@ func (bs ProjectBoardList) LoadIssues() (IssueList, error) {
 // UpdateProjectBoardSorting update project board sorting
 func UpdateProjectBoardSorting(bs ProjectBoardList) error {
 	for i := range bs {
-		_, err := x.ID(bs[i].ID).Cols(
+		_, err := db.DefaultContext().Engine().ID(bs[i].ID).Cols(
 			"sorting",
 		).Update(bs[i])
 		if err != nil {
diff --git a/models/project_issue.go b/models/project_issue.go
index e35307158..acc0a31e1 100644
--- a/models/project_issue.go
+++ b/models/project_issue.go
@@ -7,6 +7,8 @@ package models
 import (
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
+
 	"xorm.io/xorm"
 )
 
@@ -20,7 +22,11 @@ type ProjectIssue struct {
 	ProjectBoardID int64 `xorm:"INDEX"`
 }
 
-func deleteProjectIssuesByProjectID(e Engine, projectID int64) error {
+func init() {
+	db.RegisterModel(new(ProjectIssue))
+}
+
+func deleteProjectIssuesByProjectID(e db.Engine, projectID int64) error {
 	_, err := e.Where("project_id=?", projectID).Delete(&ProjectIssue{})
 	return err
 }
@@ -33,10 +39,10 @@ func deleteProjectIssuesByProjectID(e Engine, projectID int64) error {
 
 // LoadProject load the project the issue was assigned to
 func (i *Issue) LoadProject() (err error) {
-	return i.loadProject(x)
+	return i.loadProject(db.DefaultContext().Engine())
 }
 
-func (i *Issue) loadProject(e Engine) (err error) {
+func (i *Issue) loadProject(e db.Engine) (err error) {
 	if i.Project == nil {
 		var p Project
 		if _, err = e.Table("project").
@@ -52,10 +58,10 @@ func (i *Issue) loadProject(e Engine) (err error) {
 
 // ProjectID return project id if issue was assigned to one
 func (i *Issue) ProjectID() int64 {
-	return i.projectID(x)
+	return i.projectID(db.DefaultContext().Engine())
 }
 
-func (i *Issue) projectID(e Engine) int64 {
+func (i *Issue) projectID(e db.Engine) int64 {
 	var ip ProjectIssue
 	has, err := e.Where("issue_id=?", i.ID).Get(&ip)
 	if err != nil || !has {
@@ -66,10 +72,10 @@ func (i *Issue) projectID(e Engine) int64 {
 
 // ProjectBoardID return project board id if issue was assigned to one
 func (i *Issue) ProjectBoardID() int64 {
-	return i.projectBoardID(x)
+	return i.projectBoardID(db.DefaultContext().Engine())
 }
 
-func (i *Issue) projectBoardID(e Engine) int64 {
+func (i *Issue) projectBoardID(e db.Engine) int64 {
 	var ip ProjectIssue
 	has, err := e.Where("issue_id=?", i.ID).Get(&ip)
 	if err != nil || !has {
@@ -87,7 +93,7 @@ func (i *Issue) projectBoardID(e Engine) int64 {
 
 // NumIssues return counter of all issues assigned to a project
 func (p *Project) NumIssues() int {
-	c, err := x.Table("project_issue").
+	c, err := db.DefaultContext().Engine().Table("project_issue").
 		Where("project_id=?", p.ID).
 		GroupBy("issue_id").
 		Cols("issue_id").
@@ -100,7 +106,7 @@ func (p *Project) NumIssues() int {
 
 // NumClosedIssues return counter of closed issues assigned to a project
 func (p *Project) NumClosedIssues() int {
-	c, err := x.Table("project_issue").
+	c, err := db.DefaultContext().Engine().Table("project_issue").
 		Join("INNER", "issue", "project_issue.issue_id=issue.id").
 		Where("project_issue.project_id=? AND issue.is_closed=?", p.ID, true).
 		Cols("issue_id").
@@ -113,7 +119,7 @@ func (p *Project) NumClosedIssues() int {
 
 // NumOpenIssues return counter of open issues assigned to a project
 func (p *Project) NumOpenIssues() int {
-	c, err := x.Table("project_issue").
+	c, err := db.DefaultContext().Engine().Table("project_issue").
 		Join("INNER", "issue", "project_issue.issue_id=issue.id").
 		Where("project_issue.project_id=? AND issue.is_closed=?", p.ID, false).Count("issue.id")
 	if err != nil {
@@ -124,7 +130,7 @@ func (p *Project) NumOpenIssues() int {
 
 // ChangeProjectAssign changes the project associated with an issue
 func ChangeProjectAssign(issue *Issue, doer *User, newProjectID int64) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -177,7 +183,7 @@ func addUpdateIssueProject(e *xorm.Session, issue *Issue, doer *User, newProject
 
 // MoveIssueAcrossProjectBoards move a card from one board to another
 func MoveIssueAcrossProjectBoards(issue *Issue, board *ProjectBoard) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -201,7 +207,7 @@ func MoveIssueAcrossProjectBoards(issue *Issue, board *ProjectBoard) error {
 	return sess.Commit()
 }
 
-func (pb *ProjectBoard) removeIssues(e Engine) error {
+func (pb *ProjectBoard) removeIssues(e db.Engine) error {
 	_, err := e.Exec("UPDATE `project_issue` SET project_board_id = 0 WHERE project_board_id = ? ", pb.ID)
 	return err
 }
diff --git a/models/project_test.go b/models/project_test.go
index 23ad56eb3..8c630d8be 100644
--- a/models/project_test.go
+++ b/models/project_test.go
@@ -7,6 +7,7 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/timeutil"
 
 	"github.com/stretchr/testify/assert"
@@ -31,7 +32,7 @@ func TestIsProjectTypeValid(t *testing.T) {
 }
 
 func TestGetProjects(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	projects, _, err := GetProjects(ProjectSearchOptions{RepoID: 1})
 	assert.NoError(t, err)
@@ -47,7 +48,7 @@ func TestGetProjects(t *testing.T) {
 }
 
 func TestProject(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	project := &Project{
 		Type:        ProjectTypeRepository,
diff --git a/models/protected_tag.go b/models/protected_tag.go
index 88f20dd29..0ce997e99 100644
--- a/models/protected_tag.go
+++ b/models/protected_tag.go
@@ -8,6 +8,7 @@ import (
 	"regexp"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/timeutil"
 
@@ -28,21 +29,25 @@ type ProtectedTag struct {
 	UpdatedUnix timeutil.TimeStamp `xorm:"updated"`
 }
 
+func init() {
+	db.RegisterModel(new(ProtectedTag))
+}
+
 // InsertProtectedTag inserts a protected tag to database
 func InsertProtectedTag(pt *ProtectedTag) error {
-	_, err := x.Insert(pt)
+	_, err := db.DefaultContext().Engine().Insert(pt)
 	return err
 }
 
 // UpdateProtectedTag updates the protected tag
 func UpdateProtectedTag(pt *ProtectedTag) error {
-	_, err := x.ID(pt.ID).AllCols().Update(pt)
+	_, err := db.DefaultContext().Engine().ID(pt.ID).AllCols().Update(pt)
 	return err
 }
 
 // DeleteProtectedTag deletes a protected tag by ID
 func DeleteProtectedTag(pt *ProtectedTag) error {
-	_, err := x.ID(pt.ID).Delete(&ProtectedTag{})
+	_, err := db.DefaultContext().Engine().ID(pt.ID).Delete(&ProtectedTag{})
 	return err
 }
 
@@ -81,13 +86,13 @@ func (pt *ProtectedTag) IsUserAllowed(userID int64) (bool, error) {
 // GetProtectedTags gets all protected tags of the repository
 func (repo *Repository) GetProtectedTags() ([]*ProtectedTag, error) {
 	tags := make([]*ProtectedTag, 0)
-	return tags, x.Find(&tags, &ProtectedTag{RepoID: repo.ID})
+	return tags, db.DefaultContext().Engine().Find(&tags, &ProtectedTag{RepoID: repo.ID})
 }
 
 // GetProtectedTagByID gets the protected tag with the specific id
 func GetProtectedTagByID(id int64) (*ProtectedTag, error) {
 	tag := new(ProtectedTag)
-	has, err := x.ID(id).Get(tag)
+	has, err := db.DefaultContext().Engine().ID(id).Get(tag)
 	if err != nil {
 		return nil, err
 	}
diff --git a/models/protected_tag_test.go b/models/protected_tag_test.go
index 3dc895c69..fd29f7e64 100644
--- a/models/protected_tag_test.go
+++ b/models/protected_tag_test.go
@@ -7,11 +7,12 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestIsUserAllowed(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	pt := &ProtectedTag{}
 	allowed, err := pt.IsUserAllowed(1)
diff --git a/models/pull.go b/models/pull.go
index ea8f28999..925167357 100644
--- a/models/pull.go
+++ b/models/pull.go
@@ -10,6 +10,7 @@ import (
 	"io"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/timeutil"
@@ -84,6 +85,10 @@ type PullRequest struct {
 	Flow PullRequestFlow `xorm:"NOT NULL DEFAULT 0"`
 }
 
+func init() {
+	db.RegisterModel(new(PullRequest))
+}
+
 // MustHeadUserName returns the HeadRepo's username if failed return blank
 func (pr *PullRequest) MustHeadUserName() string {
 	if err := pr.LoadHeadRepo(); err != nil {
@@ -101,7 +106,7 @@ func (pr *PullRequest) MustHeadUserName() string {
 }
 
 // Note: don't try to get Issue because will end up recursive querying.
-func (pr *PullRequest) loadAttributes(e Engine) (err error) {
+func (pr *PullRequest) loadAttributes(e db.Engine) (err error) {
 	if pr.HasMerged && pr.Merger == nil {
 		pr.Merger, err = getUserByID(e, pr.MergerID)
 		if IsErrUserNotExist(err) {
@@ -117,10 +122,10 @@ func (pr *PullRequest) loadAttributes(e Engine) (err error) {
 
 // LoadAttributes loads pull request attributes from database
 func (pr *PullRequest) LoadAttributes() error {
-	return pr.loadAttributes(x)
+	return pr.loadAttributes(db.DefaultContext().Engine())
 }
 
-func (pr *PullRequest) loadHeadRepo(e Engine) (err error) {
+func (pr *PullRequest) loadHeadRepo(e db.Engine) (err error) {
 	if !pr.isHeadRepoLoaded && pr.HeadRepo == nil && pr.HeadRepoID > 0 {
 		if pr.HeadRepoID == pr.BaseRepoID {
 			if pr.BaseRepo != nil {
@@ -143,15 +148,15 @@ func (pr *PullRequest) loadHeadRepo(e Engine) (err error) {
 
 // LoadHeadRepo loads the head repository
 func (pr *PullRequest) LoadHeadRepo() error {
-	return pr.loadHeadRepo(x)
+	return pr.loadHeadRepo(db.DefaultContext().Engine())
 }
 
 // LoadBaseRepo loads the target repository
 func (pr *PullRequest) LoadBaseRepo() error {
-	return pr.loadBaseRepo(x)
+	return pr.loadBaseRepo(db.DefaultContext().Engine())
 }
 
-func (pr *PullRequest) loadBaseRepo(e Engine) (err error) {
+func (pr *PullRequest) loadBaseRepo(e db.Engine) (err error) {
 	if pr.BaseRepo != nil {
 		return nil
 	}
@@ -175,10 +180,10 @@ func (pr *PullRequest) loadBaseRepo(e Engine) (err error) {
 
 // LoadIssue loads issue information from database
 func (pr *PullRequest) LoadIssue() (err error) {
-	return pr.loadIssue(x)
+	return pr.loadIssue(db.DefaultContext().Engine())
 }
 
-func (pr *PullRequest) loadIssue(e Engine) (err error) {
+func (pr *PullRequest) loadIssue(e db.Engine) (err error) {
 	if pr.Issue != nil {
 		return nil
 	}
@@ -192,10 +197,10 @@ func (pr *PullRequest) loadIssue(e Engine) (err error) {
 
 // LoadProtectedBranch loads the protected branch of the base branch
 func (pr *PullRequest) LoadProtectedBranch() (err error) {
-	return pr.loadProtectedBranch(x)
+	return pr.loadProtectedBranch(db.DefaultContext().Engine())
 }
 
-func (pr *PullRequest) loadProtectedBranch(e Engine) (err error) {
+func (pr *PullRequest) loadProtectedBranch(e db.Engine) (err error) {
 	if pr.ProtectedBranch == nil {
 		if pr.BaseRepo == nil {
 			if pr.BaseRepoID == 0 {
@@ -252,10 +257,10 @@ type ReviewCount struct {
 // GetApprovalCounts returns the approval counts by type
 // FIXME: Only returns official counts due to double counting of non-official counts
 func (pr *PullRequest) GetApprovalCounts() ([]*ReviewCount, error) {
-	return pr.getApprovalCounts(x)
+	return pr.getApprovalCounts(db.DefaultContext().Engine())
 }
 
-func (pr *PullRequest) getApprovalCounts(e Engine) ([]*ReviewCount, error) {
+func (pr *PullRequest) getApprovalCounts(e db.Engine) ([]*ReviewCount, error) {
 	rCounts := make([]*ReviewCount, 0, 6)
 	sess := e.Where("issue_id = ?", pr.IssueID)
 	return rCounts, sess.Select("issue_id, type, count(id) as `count`").Where("official = ? AND dismissed = ?", true, false).GroupBy("issue_id, type").Table("review").Find(&rCounts)
@@ -279,7 +284,7 @@ func (pr *PullRequest) getReviewedByLines(writer io.Writer) error {
 		return nil
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -388,7 +393,7 @@ func (pr *PullRequest) SetMerged() (bool, error) {
 
 	pr.HasMerged = true
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return false, err
@@ -443,14 +448,14 @@ func (pr *PullRequest) SetMerged() (bool, error) {
 
 // NewPullRequest creates new pull request with labels for repository.
 func NewPullRequest(repo *Repository, issue *Issue, labelIDs []int64, uuids []string, pr *PullRequest) (err error) {
-	idx, err := GetNextResourceIndex("issue_index", repo.ID)
+	idx, err := db.GetNextResourceIndex("issue_index", repo.ID)
 	if err != nil {
 		return fmt.Errorf("generate issue index failed: %v", err)
 	}
 
 	issue.Index = idx
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -487,7 +492,7 @@ func NewPullRequest(repo *Repository, issue *Issue, labelIDs []int64, uuids []st
 // by given head/base and repo/branch.
 func GetUnmergedPullRequest(headRepoID, baseRepoID int64, headBranch, baseBranch string, flow PullRequestFlow) (*PullRequest, error) {
 	pr := new(PullRequest)
-	has, err := x.
+	has, err := db.DefaultContext().Engine().
 		Where("head_repo_id=? AND head_branch=? AND base_repo_id=? AND base_branch=? AND has_merged=? AND flow = ? AND issue.is_closed=?",
 			headRepoID, headBranch, baseRepoID, baseBranch, false, flow, false).
 		Join("INNER", "issue", "issue.id=pull_request.issue_id").
@@ -505,7 +510,7 @@ func GetUnmergedPullRequest(headRepoID, baseRepoID int64, headBranch, baseBranch
 // by given head information (repo and branch).
 func GetLatestPullRequestByHeadInfo(repoID int64, branch string) (*PullRequest, error) {
 	pr := new(PullRequest)
-	has, err := x.
+	has, err := db.DefaultContext().Engine().
 		Where("head_repo_id = ? AND head_branch = ? AND flow = ?", repoID, branch, PullRequestFlowGithub).
 		OrderBy("id DESC").
 		Get(pr)
@@ -522,7 +527,7 @@ func GetPullRequestByIndex(repoID, index int64) (*PullRequest, error) {
 		Index:      index,
 	}
 
-	has, err := x.Get(pr)
+	has, err := db.DefaultContext().Engine().Get(pr)
 	if err != nil {
 		return nil, err
 	} else if !has {
@@ -539,7 +544,7 @@ func GetPullRequestByIndex(repoID, index int64) (*PullRequest, error) {
 	return pr, nil
 }
 
-func getPullRequestByID(e Engine, id int64) (*PullRequest, error) {
+func getPullRequestByID(e db.Engine, id int64) (*PullRequest, error) {
 	pr := new(PullRequest)
 	has, err := e.ID(id).Get(pr)
 	if err != nil {
@@ -552,13 +557,13 @@ func getPullRequestByID(e Engine, id int64) (*PullRequest, error) {
 
 // GetPullRequestByID returns a pull request by given ID.
 func GetPullRequestByID(id int64) (*PullRequest, error) {
-	return getPullRequestByID(x, id)
+	return getPullRequestByID(db.DefaultContext().Engine(), id)
 }
 
 // GetPullRequestByIssueIDWithNoAttributes returns pull request with no attributes loaded by given issue ID.
 func GetPullRequestByIssueIDWithNoAttributes(issueID int64) (*PullRequest, error) {
 	var pr PullRequest
-	has, err := x.Where("issue_id = ?", issueID).Get(&pr)
+	has, err := db.DefaultContext().Engine().Where("issue_id = ?", issueID).Get(&pr)
 	if err != nil {
 		return nil, err
 	}
@@ -568,7 +573,7 @@ func GetPullRequestByIssueIDWithNoAttributes(issueID int64) (*PullRequest, error
 	return &pr, nil
 }
 
-func getPullRequestByIssueID(e Engine, issueID int64) (*PullRequest, error) {
+func getPullRequestByIssueID(e db.Engine, issueID int64) (*PullRequest, error) {
 	pr := &PullRequest{
 		IssueID: issueID,
 	}
@@ -586,7 +591,7 @@ func getPullRequestByIssueID(e Engine, issueID int64) (*PullRequest, error) {
 func GetAllUnmergedAgitPullRequestByPoster(uid int64) ([]*PullRequest, error) {
 	pulls := make([]*PullRequest, 0, 10)
 
-	err := x.
+	err := db.DefaultContext().Engine().
 		Where("has_merged=? AND flow = ? AND issue.is_closed=? AND issue.poster_id=?",
 			false, PullRequestFlowAGit, false, uid).
 		Join("INNER", "issue", "issue.id=pull_request.issue_id").
@@ -597,24 +602,24 @@ func GetAllUnmergedAgitPullRequestByPoster(uid int64) ([]*PullRequest, error) {
 
 // GetPullRequestByIssueID returns pull request by given issue ID.
 func GetPullRequestByIssueID(issueID int64) (*PullRequest, error) {
-	return getPullRequestByIssueID(x, issueID)
+	return getPullRequestByIssueID(db.DefaultContext().Engine(), issueID)
 }
 
 // Update updates all fields of pull request.
 func (pr *PullRequest) Update() error {
-	_, err := x.ID(pr.ID).AllCols().Update(pr)
+	_, err := db.DefaultContext().Engine().ID(pr.ID).AllCols().Update(pr)
 	return err
 }
 
 // UpdateCols updates specific fields of pull request.
 func (pr *PullRequest) UpdateCols(cols ...string) error {
-	_, err := x.ID(pr.ID).Cols(cols...).Update(pr)
+	_, err := db.DefaultContext().Engine().ID(pr.ID).Cols(cols...).Update(pr)
 	return err
 }
 
 // UpdateColsIfNotMerged updates specific fields of a pull request if it has not been merged
 func (pr *PullRequest) UpdateColsIfNotMerged(cols ...string) error {
-	_, err := x.Where("id = ? AND has_merged = ?", pr.ID, false).Cols(cols...).Update(pr)
+	_, err := db.DefaultContext().Engine().Where("id = ? AND has_merged = ?", pr.ID, false).Cols(cols...).Update(pr)
 	return err
 }
 
@@ -660,10 +665,10 @@ func (pr *PullRequest) GetWorkInProgressPrefix() string {
 
 // UpdateCommitDivergence update Divergence of a pull request
 func (pr *PullRequest) UpdateCommitDivergence(ahead, behind int) error {
-	return pr.updateCommitDivergence(x, ahead, behind)
+	return pr.updateCommitDivergence(db.DefaultContext().Engine(), ahead, behind)
 }
 
-func (pr *PullRequest) updateCommitDivergence(e Engine, ahead, behind int) error {
+func (pr *PullRequest) updateCommitDivergence(e db.Engine, ahead, behind int) error {
 	if pr.ID == 0 {
 		return fmt.Errorf("pull ID is 0")
 	}
diff --git a/models/pull_list.go b/models/pull_list.go
index 8fa80307d..ed8372658 100644
--- a/models/pull_list.go
+++ b/models/pull_list.go
@@ -7,6 +7,7 @@ package models
 import (
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
@@ -24,7 +25,7 @@ type PullRequestsOptions struct {
 }
 
 func listPullRequestStatement(baseRepoID int64, opts *PullRequestsOptions) (*xorm.Session, error) {
-	sess := x.Where("pull_request.base_repo_id=?", baseRepoID)
+	sess := db.DefaultContext().Engine().Where("pull_request.base_repo_id=?", baseRepoID)
 
 	sess.Join("INNER", "issue", "pull_request.issue_id = issue.id")
 	switch opts.State {
@@ -50,7 +51,7 @@ func listPullRequestStatement(baseRepoID int64, opts *PullRequestsOptions) (*xor
 // by given head information (repo and branch).
 func GetUnmergedPullRequestsByHeadInfo(repoID int64, branch string) ([]*PullRequest, error) {
 	prs := make([]*PullRequest, 0, 2)
-	return prs, x.
+	return prs, db.DefaultContext().Engine().
 		Where("head_repo_id = ? AND head_branch = ? AND has_merged = ? AND issue.is_closed = ? AND flow = ?",
 			repoID, branch, false, false, PullRequestFlowGithub).
 		Join("INNER", "issue", "issue.id = pull_request.issue_id").
@@ -61,7 +62,7 @@ func GetUnmergedPullRequestsByHeadInfo(repoID int64, branch string) ([]*PullRequ
 // by given base information (repo and branch).
 func GetUnmergedPullRequestsByBaseInfo(repoID int64, branch string) ([]*PullRequest, error) {
 	prs := make([]*PullRequest, 0, 2)
-	return prs, x.
+	return prs, db.DefaultContext().Engine().
 		Where("base_repo_id=? AND base_branch=? AND has_merged=? AND issue.is_closed=?",
 			repoID, branch, false, false).
 		Join("INNER", "issue", "issue.id=pull_request.issue_id").
@@ -71,7 +72,7 @@ func GetUnmergedPullRequestsByBaseInfo(repoID int64, branch string) ([]*PullRequ
 // GetPullRequestIDsByCheckStatus returns all pull requests according the special checking status.
 func GetPullRequestIDsByCheckStatus(status PullRequestStatus) ([]int64, error) {
 	prs := make([]int64, 0, 10)
-	return prs, x.Table("pull_request").
+	return prs, db.DefaultContext().Engine().Table("pull_request").
 		Where("status=?", status).
 		Cols("pull_request.id").
 		Find(&prs)
@@ -108,7 +109,7 @@ func PullRequests(baseRepoID int64, opts *PullRequestsOptions) ([]*PullRequest,
 // PullRequestList defines a list of pull requests
 type PullRequestList []*PullRequest
 
-func (prs PullRequestList) loadAttributes(e Engine) error {
+func (prs PullRequestList) loadAttributes(e db.Engine) error {
 	if len(prs) == 0 {
 		return nil
 	}
@@ -143,10 +144,10 @@ func (prs PullRequestList) getIssueIDs() []int64 {
 
 // LoadAttributes load all the prs attributes
 func (prs PullRequestList) LoadAttributes() error {
-	return prs.loadAttributes(x)
+	return prs.loadAttributes(db.DefaultContext().Engine())
 }
 
-func (prs PullRequestList) invalidateCodeComments(e Engine, doer *User, repo *git.Repository, branch string) error {
+func (prs PullRequestList) invalidateCodeComments(e db.Engine, doer *User, repo *git.Repository, branch string) error {
 	if len(prs) == 0 {
 		return nil
 	}
@@ -168,5 +169,5 @@ func (prs PullRequestList) invalidateCodeComments(e Engine, doer *User, repo *gi
 
 // InvalidateCodeComments will lookup the prs for code comments which got invalidated by change
 func (prs PullRequestList) InvalidateCodeComments(doer *User, repo *git.Repository, branch string) error {
-	return prs.invalidateCodeComments(x, doer, repo, branch)
+	return prs.invalidateCodeComments(db.DefaultContext().Engine(), doer, repo, branch)
 }
diff --git a/models/pull_test.go b/models/pull_test.go
index 07216da32..6543d0ec9 100644
--- a/models/pull_test.go
+++ b/models/pull_test.go
@@ -7,20 +7,21 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestPullRequest_LoadAttributes(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	pr := AssertExistsAndLoadBean(t, &PullRequest{ID: 1}).(*PullRequest)
+	assert.NoError(t, db.PrepareTestDatabase())
+	pr := db.AssertExistsAndLoadBean(t, &PullRequest{ID: 1}).(*PullRequest)
 	assert.NoError(t, pr.LoadAttributes())
 	assert.NotNil(t, pr.Merger)
 	assert.Equal(t, pr.MergerID, pr.Merger.ID)
 }
 
 func TestPullRequest_LoadIssue(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	pr := AssertExistsAndLoadBean(t, &PullRequest{ID: 1}).(*PullRequest)
+	assert.NoError(t, db.PrepareTestDatabase())
+	pr := db.AssertExistsAndLoadBean(t, &PullRequest{ID: 1}).(*PullRequest)
 	assert.NoError(t, pr.LoadIssue())
 	assert.NotNil(t, pr.Issue)
 	assert.Equal(t, int64(2), pr.Issue.ID)
@@ -30,8 +31,8 @@ func TestPullRequest_LoadIssue(t *testing.T) {
 }
 
 func TestPullRequest_LoadBaseRepo(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	pr := AssertExistsAndLoadBean(t, &PullRequest{ID: 1}).(*PullRequest)
+	assert.NoError(t, db.PrepareTestDatabase())
+	pr := db.AssertExistsAndLoadBean(t, &PullRequest{ID: 1}).(*PullRequest)
 	assert.NoError(t, pr.LoadBaseRepo())
 	assert.NotNil(t, pr.BaseRepo)
 	assert.Equal(t, pr.BaseRepoID, pr.BaseRepo.ID)
@@ -41,8 +42,8 @@ func TestPullRequest_LoadBaseRepo(t *testing.T) {
 }
 
 func TestPullRequest_LoadHeadRepo(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	pr := AssertExistsAndLoadBean(t, &PullRequest{ID: 1}).(*PullRequest)
+	assert.NoError(t, db.PrepareTestDatabase())
+	pr := db.AssertExistsAndLoadBean(t, &PullRequest{ID: 1}).(*PullRequest)
 	assert.NoError(t, pr.LoadHeadRepo())
 	assert.NotNil(t, pr.HeadRepo)
 	assert.Equal(t, pr.HeadRepoID, pr.HeadRepo.ID)
@@ -53,7 +54,7 @@ func TestPullRequest_LoadHeadRepo(t *testing.T) {
 // TODO TestNewPullRequest
 
 func TestPullRequestsNewest(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	prs, count, err := PullRequests(1, &PullRequestsOptions{
 		ListOptions: ListOptions{
 			Page: 1,
@@ -72,7 +73,7 @@ func TestPullRequestsNewest(t *testing.T) {
 }
 
 func TestPullRequestsOldest(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	prs, count, err := PullRequests(1, &PullRequestsOptions{
 		ListOptions: ListOptions{
 			Page: 1,
@@ -91,7 +92,7 @@ func TestPullRequestsOldest(t *testing.T) {
 }
 
 func TestGetUnmergedPullRequest(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	pr, err := GetUnmergedPullRequest(1, 1, "branch2", "master", PullRequestFlowGithub)
 	assert.NoError(t, err)
 	assert.Equal(t, int64(2), pr.ID)
@@ -102,7 +103,7 @@ func TestGetUnmergedPullRequest(t *testing.T) {
 }
 
 func TestGetUnmergedPullRequestsByHeadInfo(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	prs, err := GetUnmergedPullRequestsByHeadInfo(1, "branch2")
 	assert.NoError(t, err)
 	assert.Len(t, prs, 1)
@@ -113,7 +114,7 @@ func TestGetUnmergedPullRequestsByHeadInfo(t *testing.T) {
 }
 
 func TestGetUnmergedPullRequestsByBaseInfo(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	prs, err := GetUnmergedPullRequestsByBaseInfo(1, "master")
 	assert.NoError(t, err)
 	assert.Len(t, prs, 1)
@@ -124,7 +125,7 @@ func TestGetUnmergedPullRequestsByBaseInfo(t *testing.T) {
 }
 
 func TestGetPullRequestByIndex(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	pr, err := GetPullRequestByIndex(1, 2)
 	assert.NoError(t, err)
 	assert.Equal(t, int64(1), pr.BaseRepoID)
@@ -136,7 +137,7 @@ func TestGetPullRequestByIndex(t *testing.T) {
 }
 
 func TestGetPullRequestByID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	pr, err := GetPullRequestByID(1)
 	assert.NoError(t, err)
 	assert.Equal(t, int64(1), pr.ID)
@@ -148,7 +149,7 @@ func TestGetPullRequestByID(t *testing.T) {
 }
 
 func TestGetPullRequestByIssueID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	pr, err := GetPullRequestByIssueID(2)
 	assert.NoError(t, err)
 	assert.Equal(t, int64(2), pr.IssueID)
@@ -159,20 +160,20 @@ func TestGetPullRequestByIssueID(t *testing.T) {
 }
 
 func TestPullRequest_Update(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	pr := AssertExistsAndLoadBean(t, &PullRequest{ID: 1}).(*PullRequest)
+	assert.NoError(t, db.PrepareTestDatabase())
+	pr := db.AssertExistsAndLoadBean(t, &PullRequest{ID: 1}).(*PullRequest)
 	pr.BaseBranch = "baseBranch"
 	pr.HeadBranch = "headBranch"
 	pr.Update()
 
-	pr = AssertExistsAndLoadBean(t, &PullRequest{ID: pr.ID}).(*PullRequest)
+	pr = db.AssertExistsAndLoadBean(t, &PullRequest{ID: pr.ID}).(*PullRequest)
 	assert.Equal(t, "baseBranch", pr.BaseBranch)
 	assert.Equal(t, "headBranch", pr.HeadBranch)
 	CheckConsistencyFor(t, pr)
 }
 
 func TestPullRequest_UpdateCols(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	pr := &PullRequest{
 		ID:         1,
 		BaseBranch: "baseBranch",
@@ -180,18 +181,18 @@ func TestPullRequest_UpdateCols(t *testing.T) {
 	}
 	assert.NoError(t, pr.UpdateCols("head_branch"))
 
-	pr = AssertExistsAndLoadBean(t, &PullRequest{ID: 1}).(*PullRequest)
+	pr = db.AssertExistsAndLoadBean(t, &PullRequest{ID: 1}).(*PullRequest)
 	assert.Equal(t, "master", pr.BaseBranch)
 	assert.Equal(t, "headBranch", pr.HeadBranch)
 	CheckConsistencyFor(t, pr)
 }
 
 func TestPullRequestList_LoadAttributes(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	prs := []*PullRequest{
-		AssertExistsAndLoadBean(t, &PullRequest{ID: 1}).(*PullRequest),
-		AssertExistsAndLoadBean(t, &PullRequest{ID: 2}).(*PullRequest),
+		db.AssertExistsAndLoadBean(t, &PullRequest{ID: 1}).(*PullRequest),
+		db.AssertExistsAndLoadBean(t, &PullRequest{ID: 2}).(*PullRequest),
 	}
 	assert.NoError(t, PullRequestList(prs).LoadAttributes())
 	for _, pr := range prs {
@@ -205,9 +206,9 @@ func TestPullRequestList_LoadAttributes(t *testing.T) {
 // TODO TestAddTestPullRequestTask
 
 func TestPullRequest_IsWorkInProgress(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	pr := AssertExistsAndLoadBean(t, &PullRequest{ID: 2}).(*PullRequest)
+	pr := db.AssertExistsAndLoadBean(t, &PullRequest{ID: 2}).(*PullRequest)
 	pr.LoadIssue()
 
 	assert.False(t, pr.IsWorkInProgress())
@@ -220,9 +221,9 @@ func TestPullRequest_IsWorkInProgress(t *testing.T) {
 }
 
 func TestPullRequest_GetWorkInProgressPrefixWorkInProgress(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	pr := AssertExistsAndLoadBean(t, &PullRequest{ID: 2}).(*PullRequest)
+	pr := db.AssertExistsAndLoadBean(t, &PullRequest{ID: 2}).(*PullRequest)
 	pr.LoadIssue()
 
 	assert.Empty(t, pr.GetWorkInProgressPrefix())
@@ -236,8 +237,8 @@ func TestPullRequest_GetWorkInProgressPrefixWorkInProgress(t *testing.T) {
 }
 
 func TestPullRequest_GetDefaultMergeMessage_InternalTracker(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	pr := AssertExistsAndLoadBean(t, &PullRequest{ID: 2}).(*PullRequest)
+	assert.NoError(t, db.PrepareTestDatabase())
+	pr := db.AssertExistsAndLoadBean(t, &PullRequest{ID: 2}).(*PullRequest)
 
 	assert.Equal(t, "Merge pull request 'issue3' (#3) from branch2 into master", pr.GetDefaultMergeMessage())
 
@@ -247,7 +248,7 @@ func TestPullRequest_GetDefaultMergeMessage_InternalTracker(t *testing.T) {
 }
 
 func TestPullRequest_GetDefaultMergeMessage_ExternalTracker(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	externalTracker := RepoUnit{
 		Type: UnitTypeExternalTracker,
@@ -259,7 +260,7 @@ func TestPullRequest_GetDefaultMergeMessage_ExternalTracker(t *testing.T) {
 	baseRepo.Owner = &User{Name: "testOwner"}
 	baseRepo.Units = []*RepoUnit{&externalTracker}
 
-	pr := AssertExistsAndLoadBean(t, &PullRequest{ID: 2, BaseRepo: baseRepo}).(*PullRequest)
+	pr := db.AssertExistsAndLoadBean(t, &PullRequest{ID: 2, BaseRepo: baseRepo}).(*PullRequest)
 
 	assert.Equal(t, "Merge pull request 'issue3' (!3) from branch2 into master", pr.GetDefaultMergeMessage())
 
diff --git a/models/release.go b/models/release.go
index 7def2f1cb..2a6e9352f 100644
--- a/models/release.go
+++ b/models/release.go
@@ -11,6 +11,7 @@ import (
 	"sort"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/timeutil"
@@ -44,7 +45,11 @@ type Release struct {
 	CreatedUnix      timeutil.TimeStamp `xorm:"INDEX"`
 }
 
-func (r *Release) loadAttributes(e Engine) error {
+func init() {
+	db.RegisterModel(new(Release))
+}
+
+func (r *Release) loadAttributes(e db.Engine) error {
 	var err error
 	if r.Repo == nil {
 		r.Repo, err = GetRepositoryByID(r.RepoID)
@@ -67,7 +72,7 @@ func (r *Release) loadAttributes(e Engine) error {
 
 // LoadAttributes load repo and publisher attributes for a release
 func (r *Release) LoadAttributes() error {
-	return r.loadAttributes(x)
+	return r.loadAttributes(db.DefaultContext().Engine())
 }
 
 // APIURL the api url for a release. release must have attributes loaded
@@ -97,31 +102,31 @@ func IsReleaseExist(repoID int64, tagName string) (bool, error) {
 		return false, nil
 	}
 
-	return x.Get(&Release{RepoID: repoID, LowerTagName: strings.ToLower(tagName)})
+	return db.DefaultContext().Engine().Get(&Release{RepoID: repoID, LowerTagName: strings.ToLower(tagName)})
 }
 
 // InsertRelease inserts a release
 func InsertRelease(rel *Release) error {
-	_, err := x.Insert(rel)
+	_, err := db.DefaultContext().Engine().Insert(rel)
 	return err
 }
 
 // InsertReleasesContext insert releases
-func InsertReleasesContext(ctx DBContext, rels []*Release) error {
-	_, err := ctx.e.Insert(rels)
+func InsertReleasesContext(ctx *db.Context, rels []*Release) error {
+	_, err := ctx.Engine().Insert(rels)
 	return err
 }
 
 // UpdateRelease updates all columns of a release
-func UpdateRelease(ctx DBContext, rel *Release) error {
-	_, err := ctx.e.ID(rel.ID).AllCols().Update(rel)
+func UpdateRelease(ctx *db.Context, rel *Release) error {
+	_, err := ctx.Engine().ID(rel.ID).AllCols().Update(rel)
 	return err
 }
 
 // AddReleaseAttachments adds a release attachments
-func AddReleaseAttachments(ctx DBContext, releaseID int64, attachmentUUIDs []string) (err error) {
+func AddReleaseAttachments(ctx *db.Context, releaseID int64, attachmentUUIDs []string) (err error) {
 	// Check attachments
-	attachments, err := getAttachmentsByUUIDs(ctx.e, attachmentUUIDs)
+	attachments, err := getAttachmentsByUUIDs(ctx.Engine(), attachmentUUIDs)
 	if err != nil {
 		return fmt.Errorf("GetAttachmentsByUUIDs [uuids: %v]: %v", attachmentUUIDs, err)
 	}
@@ -132,7 +137,7 @@ func AddReleaseAttachments(ctx DBContext, releaseID int64, attachmentUUIDs []str
 		}
 		attachments[i].ReleaseID = releaseID
 		// No assign value could be 0, so ignore AllCols().
-		if _, err = ctx.e.ID(attachments[i].ID).Update(attachments[i]); err != nil {
+		if _, err = ctx.Engine().ID(attachments[i].ID).Update(attachments[i]); err != nil {
 			return fmt.Errorf("update attachment [%d]: %v", attachments[i].ID, err)
 		}
 	}
@@ -150,14 +155,14 @@ func GetRelease(repoID int64, tagName string) (*Release, error) {
 	}
 
 	rel := &Release{RepoID: repoID, LowerTagName: strings.ToLower(tagName)}
-	_, err = x.Get(rel)
+	_, err = db.DefaultContext().Engine().Get(rel)
 	return rel, err
 }
 
 // GetReleaseByID returns release with given ID.
 func GetReleaseByID(id int64) (*Release, error) {
 	rel := new(Release)
-	has, err := x.
+	has, err := db.DefaultContext().Engine().
 		ID(id).
 		Get(rel)
 	if err != nil {
@@ -203,7 +208,7 @@ func (opts *FindReleasesOptions) toConds(repoID int64) builder.Cond {
 
 // GetReleasesByRepoID returns a list of releases of repository.
 func GetReleasesByRepoID(repoID int64, opts FindReleasesOptions) ([]*Release, error) {
-	sess := x.
+	sess := db.DefaultContext().Engine().
 		Desc("created_unix", "id").
 		Where(opts.toConds(repoID))
 
@@ -217,7 +222,7 @@ func GetReleasesByRepoID(repoID int64, opts FindReleasesOptions) ([]*Release, er
 
 // CountReleasesByRepoID returns a number of releases matching FindReleaseOptions and RepoID.
 func CountReleasesByRepoID(repoID int64, opts FindReleasesOptions) (int64, error) {
-	return x.Where(opts.toConds(repoID)).Count(new(Release))
+	return db.DefaultContext().Engine().Where(opts.toConds(repoID)).Count(new(Release))
 }
 
 // GetLatestReleaseByRepoID returns the latest release for a repository
@@ -229,7 +234,7 @@ func GetLatestReleaseByRepoID(repoID int64) (*Release, error) {
 		And(builder.Eq{"is_tag": false})
 
 	rel := new(Release)
-	has, err := x.
+	has, err := db.DefaultContext().Engine().
 		Desc("created_unix", "id").
 		Where(cond).
 		Get(rel)
@@ -243,8 +248,8 @@ func GetLatestReleaseByRepoID(repoID int64) (*Release, error) {
 }
 
 // GetReleasesByRepoIDAndNames returns a list of releases of repository according repoID and tagNames.
-func GetReleasesByRepoIDAndNames(ctx DBContext, repoID int64, tagNames []string) (rels []*Release, err error) {
-	err = ctx.e.
+func GetReleasesByRepoIDAndNames(ctx *db.Context, repoID int64, tagNames []string) (rels []*Release, err error) {
+	err = ctx.Engine().
 		In("tag_name", tagNames).
 		Desc("created_unix").
 		Find(&rels, Release{RepoID: repoID})
@@ -253,7 +258,7 @@ func GetReleasesByRepoIDAndNames(ctx DBContext, repoID int64, tagNames []string)
 
 // GetReleaseCountByRepoID returns the count of releases of repository
 func GetReleaseCountByRepoID(repoID int64, opts FindReleasesOptions) (int64, error) {
-	return x.Where(opts.toConds(repoID)).Count(&Release{})
+	return db.DefaultContext().Engine().Where(opts.toConds(repoID)).Count(&Release{})
 }
 
 type releaseMetaSearch struct {
@@ -276,10 +281,10 @@ func (s releaseMetaSearch) Less(i, j int) bool {
 
 // GetReleaseAttachments retrieves the attachments for releases
 func GetReleaseAttachments(rels ...*Release) (err error) {
-	return getReleaseAttachments(x, rels...)
+	return getReleaseAttachments(db.DefaultContext().Engine(), rels...)
 }
 
-func getReleaseAttachments(e Engine, rels ...*Release) (err error) {
+func getReleaseAttachments(e db.Engine, rels ...*Release) (err error) {
 	if len(rels) == 0 {
 		return
 	}
@@ -347,13 +352,13 @@ func SortReleases(rels []*Release) {
 
 // DeleteReleaseByID deletes a release from database by given ID.
 func DeleteReleaseByID(id int64) error {
-	_, err := x.ID(id).Delete(new(Release))
+	_, err := db.DefaultContext().Engine().ID(id).Delete(new(Release))
 	return err
 }
 
 // UpdateReleasesMigrationsByType updates all migrated repositories' releases from gitServiceType to replace originalAuthorID to posterID
 func UpdateReleasesMigrationsByType(gitServiceType structs.GitServiceType, originalAuthorID string, posterID int64) error {
-	_, err := x.Table("release").
+	_, err := db.DefaultContext().Engine().Table("release").
 		Where("repo_id IN (SELECT id FROM repository WHERE original_service_type = ?)", gitServiceType).
 		And("original_author_id = ?", originalAuthorID).
 		Update(map[string]interface{}{
diff --git a/models/repo.go b/models/repo.go
index 575b8acbc..914001191 100644
--- a/models/repo.go
+++ b/models/repo.go
@@ -25,6 +25,7 @@ import (
 	"strings"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/lfs"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/markup"
@@ -251,6 +252,10 @@ type Repository struct {
 	UpdatedUnix timeutil.TimeStamp `xorm:"INDEX updated"`
 }
 
+func init() {
+	db.RegisterModel(new(Repository))
+}
+
 // SanitizedOriginalURL returns a sanitized OriginalURL
 func (repo *Repository) SanitizedOriginalURL() string {
 	if repo.OriginalURL == "" {
@@ -300,7 +305,7 @@ func (repo *Repository) AfterLoad() {
 // It creates a fake object that contains error details
 // when error occurs.
 func (repo *Repository) MustOwner() *User {
-	return repo.mustOwner(x)
+	return repo.mustOwner(db.DefaultContext().Engine())
 }
 
 // FullName returns the repository full name
@@ -340,7 +345,7 @@ func (repo *Repository) GetCommitsCountCacheKey(contextName string, isRef bool)
 	return fmt.Sprintf("commits-count-%d-%s-%s", repo.ID, prefix, contextName)
 }
 
-func (repo *Repository) getUnits(e Engine) (err error) {
+func (repo *Repository) getUnits(e db.Engine) (err error) {
 	if repo.Units != nil {
 		return nil
 	}
@@ -352,10 +357,10 @@ func (repo *Repository) getUnits(e Engine) (err error) {
 
 // CheckUnitUser check whether user could visit the unit of this repository
 func (repo *Repository) CheckUnitUser(user *User, unitType UnitType) bool {
-	return repo.checkUnitUser(x, user, unitType)
+	return repo.checkUnitUser(db.DefaultContext().Engine(), user, unitType)
 }
 
-func (repo *Repository) checkUnitUser(e Engine, user *User, unitType UnitType) bool {
+func (repo *Repository) checkUnitUser(e db.Engine, user *User, unitType UnitType) bool {
 	if user.IsAdmin {
 		return true
 	}
@@ -370,7 +375,7 @@ func (repo *Repository) checkUnitUser(e Engine, user *User, unitType UnitType) b
 
 // UnitEnabled if this repository has the given unit enabled
 func (repo *Repository) UnitEnabled(tp UnitType) bool {
-	if err := repo.getUnits(x); err != nil {
+	if err := repo.getUnits(db.DefaultContext().Engine()); err != nil {
 		log.Warn("Error loading repository (ID: %d) units: %s", repo.ID, err.Error())
 	}
 	for _, unit := range repo.Units {
@@ -432,10 +437,10 @@ func (repo *Repository) MustGetUnit(tp UnitType) *RepoUnit {
 
 // GetUnit returns a RepoUnit object
 func (repo *Repository) GetUnit(tp UnitType) (*RepoUnit, error) {
-	return repo.getUnit(x, tp)
+	return repo.getUnit(db.DefaultContext().Engine(), tp)
 }
 
-func (repo *Repository) getUnit(e Engine, tp UnitType) (*RepoUnit, error) {
+func (repo *Repository) getUnit(e db.Engine, tp UnitType) (*RepoUnit, error) {
 	if err := repo.getUnits(e); err != nil {
 		return nil, err
 	}
@@ -447,7 +452,7 @@ func (repo *Repository) getUnit(e Engine, tp UnitType) (*RepoUnit, error) {
 	return nil, ErrUnitTypeNotExist{tp}
 }
 
-func (repo *Repository) getOwner(e Engine) (err error) {
+func (repo *Repository) getOwner(e db.Engine) (err error) {
 	if repo.Owner != nil {
 		return nil
 	}
@@ -458,10 +463,10 @@ func (repo *Repository) getOwner(e Engine) (err error) {
 
 // GetOwner returns the repository owner
 func (repo *Repository) GetOwner() error {
-	return repo.getOwner(x)
+	return repo.getOwner(db.DefaultContext().Engine())
 }
 
-func (repo *Repository) mustOwner(e Engine) *User {
+func (repo *Repository) mustOwner(e db.Engine) *User {
 	if err := repo.getOwner(e); err != nil {
 		return &User{
 			Name:     "error",
@@ -496,7 +501,7 @@ func (repo *Repository) ComposeMetas() map[string]string {
 		repo.MustOwner()
 		if repo.Owner.IsOrganization() {
 			teams := make([]string, 0, 5)
-			_ = x.Table("team_repo").
+			_ = db.DefaultContext().Engine().Table("team_repo").
 				Join("INNER", "team", "team.id = team_repo.team_id").
 				Where("team_repo.repo_id = ?", repo.ID).
 				Select("team.lower_name").
@@ -524,7 +529,7 @@ func (repo *Repository) ComposeDocumentMetas() map[string]string {
 	return repo.DocumentRenderingMetas
 }
 
-func (repo *Repository) getAssignees(e Engine) (_ []*User, err error) {
+func (repo *Repository) getAssignees(e db.Engine) (_ []*User, err error) {
 	if err = repo.getOwner(e); err != nil {
 		return nil, err
 	}
@@ -559,10 +564,10 @@ func (repo *Repository) getAssignees(e Engine) (_ []*User, err error) {
 // GetAssignees returns all users that have write access and can be assigned to issues
 // of the repository,
 func (repo *Repository) GetAssignees() (_ []*User, err error) {
-	return repo.getAssignees(x)
+	return repo.getAssignees(db.DefaultContext().Engine())
 }
 
-func (repo *Repository) getReviewers(e Engine, doerID, posterID int64) ([]*User, error) {
+func (repo *Repository) getReviewers(e db.Engine, doerID, posterID int64) ([]*User, error) {
 	// Get the owner of the repository - this often already pre-cached and if so saves complexity for the following queries
 	if err := repo.getOwner(e); err != nil {
 		return nil, err
@@ -611,7 +616,7 @@ func (repo *Repository) getReviewers(e Engine, doerID, posterID int64) ([]*User,
 // all repo watchers and all organization members.
 // TODO: may be we should have a busy choice for users to block review request to them.
 func (repo *Repository) GetReviewers(doerID, posterID int64) ([]*User, error) {
-	return repo.getReviewers(x, doerID, posterID)
+	return repo.getReviewers(db.DefaultContext().Engine(), doerID, posterID)
 }
 
 // GetReviewerTeams get all teams can be requested to review
@@ -657,10 +662,10 @@ func (repo *Repository) LoadPushMirrors() (err error) {
 // returns an error on failure (NOTE: no error is returned for
 // non-fork repositories, and BaseRepo will be left untouched)
 func (repo *Repository) GetBaseRepo() (err error) {
-	return repo.getBaseRepo(x)
+	return repo.getBaseRepo(db.DefaultContext().Engine())
 }
 
-func (repo *Repository) getBaseRepo(e Engine) (err error) {
+func (repo *Repository) getBaseRepo(e db.Engine) (err error) {
 	if !repo.IsFork {
 		return nil
 	}
@@ -678,10 +683,10 @@ func (repo *Repository) IsGenerated() bool {
 // returns an error on failure (NOTE: no error is returned for
 // non-generated repositories, and TemplateRepo will be left untouched)
 func (repo *Repository) GetTemplateRepo() (err error) {
-	return repo.getTemplateRepo(x)
+	return repo.getTemplateRepo(db.DefaultContext().Engine())
 }
 
-func (repo *Repository) getTemplateRepo(e Engine) (err error) {
+func (repo *Repository) getTemplateRepo(e db.Engine) (err error) {
 	if !repo.IsGenerated() {
 		return nil
 	}
@@ -722,7 +727,7 @@ func (repo *Repository) ComposeCompareURL(oldCommitID, newCommitID string) strin
 
 // UpdateDefaultBranch updates the default branch
 func (repo *Repository) UpdateDefaultBranch() error {
-	_, err := x.ID(repo.ID).Cols("default_branch").Update(repo)
+	_, err := db.DefaultContext().Engine().ID(repo.ID).Cols("default_branch").Update(repo)
 	return err
 }
 
@@ -731,7 +736,7 @@ func (repo *Repository) IsOwnedBy(userID int64) bool {
 	return repo.OwnerID == userID
 }
 
-func (repo *Repository) updateSize(e Engine) error {
+func (repo *Repository) updateSize(e db.Engine) error {
 	size, err := util.GetDirectorySize(repo.RepoPath())
 	if err != nil {
 		return fmt.Errorf("updateSize: %v", err)
@@ -748,8 +753,8 @@ func (repo *Repository) updateSize(e Engine) error {
 }
 
 // UpdateSize updates the repository size, calculating it using util.GetDirectorySize
-func (repo *Repository) UpdateSize(ctx DBContext) error {
-	return repo.updateSize(ctx.e)
+func (repo *Repository) UpdateSize(ctx *db.Context) error {
+	return repo.updateSize(ctx.Engine())
 }
 
 // CanUserFork returns true if specified user can fork repository.
@@ -810,12 +815,12 @@ func (repo *Repository) CanEnableEditor() bool {
 
 // GetReaders returns all users that have explicit read access or higher to the repository.
 func (repo *Repository) GetReaders() (_ []*User, err error) {
-	return repo.getUsersWithAccessMode(x, AccessModeRead)
+	return repo.getUsersWithAccessMode(db.DefaultContext().Engine(), AccessModeRead)
 }
 
 // GetWriters returns all users that have write access to the repository.
 func (repo *Repository) GetWriters() (_ []*User, err error) {
-	return repo.getUsersWithAccessMode(x, AccessModeWrite)
+	return repo.getUsersWithAccessMode(db.DefaultContext().Engine(), AccessModeWrite)
 }
 
 // IsReader returns true if user has explicit read access or higher to the repository.
@@ -823,11 +828,11 @@ func (repo *Repository) IsReader(userID int64) (bool, error) {
 	if repo.OwnerID == userID {
 		return true, nil
 	}
-	return x.Where("repo_id = ? AND user_id = ? AND mode >= ?", repo.ID, userID, AccessModeRead).Get(&Access{})
+	return db.DefaultContext().Engine().Where("repo_id = ? AND user_id = ? AND mode >= ?", repo.ID, userID, AccessModeRead).Get(&Access{})
 }
 
 // getUsersWithAccessMode returns users that have at least given access mode to the repository.
-func (repo *Repository) getUsersWithAccessMode(e Engine, mode AccessMode) (_ []*User, err error) {
+func (repo *Repository) getUsersWithAccessMode(e db.Engine, mode AccessMode) (_ []*User, err error) {
 	if err = repo.getOwner(e); err != nil {
 		return nil, err
 	}
@@ -872,10 +877,10 @@ func (repo *Repository) DescriptionHTML() template.HTML {
 
 // ReadBy sets repo to be visited by given user.
 func (repo *Repository) ReadBy(userID int64) error {
-	return setRepoNotificationStatusReadIfUnread(x, userID, repo.ID)
+	return setRepoNotificationStatusReadIfUnread(db.DefaultContext().Engine(), userID, repo.ID)
 }
 
-func isRepositoryExist(e Engine, u *User, repoName string) (bool, error) {
+func isRepositoryExist(e db.Engine, u *User, repoName string) (bool, error) {
 	has, err := e.Get(&Repository{
 		OwnerID:   u.ID,
 		LowerName: strings.ToLower(repoName),
@@ -889,7 +894,7 @@ func isRepositoryExist(e Engine, u *User, repoName string) (bool, error) {
 
 // IsRepositoryExist returns true if the repository with given name under user has already existed.
 func IsRepositoryExist(u *User, repoName string) (bool, error) {
-	return isRepositoryExist(x, u, repoName)
+	return isRepositoryExist(db.DefaultContext().Engine(), u, repoName)
 }
 
 // CloneLink represents different types of clone URLs of repository.
@@ -951,7 +956,7 @@ func CheckCreateRepository(doer, u *User, name string, overwriteOrAdopt bool) er
 		return err
 	}
 
-	has, err := isRepositoryExist(x, u, name)
+	has, err := isRepositoryExist(db.DefaultContext().Engine(), u, name)
 	if err != nil {
 		return fmt.Errorf("IsRepositoryExist: %v", err)
 	} else if has {
@@ -1040,12 +1045,12 @@ func IsUsableRepoName(name string) error {
 }
 
 // CreateRepository creates a repository for the user/organization.
-func CreateRepository(ctx DBContext, doer, u *User, repo *Repository, overwriteOrAdopt bool) (err error) {
+func CreateRepository(ctx *db.Context, doer, u *User, repo *Repository, overwriteOrAdopt bool) (err error) {
 	if err = IsUsableRepoName(repo.Name); err != nil {
 		return err
 	}
 
-	has, err := isRepositoryExist(ctx.e, u, repo.Name)
+	has, err := isRepositoryExist(ctx.Engine(), u, repo.Name)
 	if err != nil {
 		return fmt.Errorf("IsRepositoryExist: %v", err)
 	} else if has {
@@ -1066,10 +1071,10 @@ func CreateRepository(ctx DBContext, doer, u *User, repo *Repository, overwriteO
 		}
 	}
 
-	if _, err = ctx.e.Insert(repo); err != nil {
+	if _, err = ctx.Engine().Insert(repo); err != nil {
 		return err
 	}
-	if err = deleteRepoRedirect(ctx.e, u.ID, repo.Name); err != nil {
+	if err = deleteRepoRedirect(ctx.Engine(), u.ID, repo.Name); err != nil {
 		return err
 	}
 
@@ -1100,46 +1105,46 @@ func CreateRepository(ctx DBContext, doer, u *User, repo *Repository, overwriteO
 		}
 	}
 
-	if _, err = ctx.e.Insert(&units); err != nil {
+	if _, err = ctx.Engine().Insert(&units); err != nil {
 		return err
 	}
 
 	// Remember visibility preference.
 	u.LastRepoVisibility = repo.IsPrivate
-	if err = updateUserCols(ctx.e, u, "last_repo_visibility"); err != nil {
+	if err = updateUserCols(ctx.Engine(), u, "last_repo_visibility"); err != nil {
 		return fmt.Errorf("updateUser: %v", err)
 	}
 
-	if _, err = ctx.e.Incr("num_repos").ID(u.ID).Update(new(User)); err != nil {
+	if _, err = ctx.Engine().Incr("num_repos").ID(u.ID).Update(new(User)); err != nil {
 		return fmt.Errorf("increment user total_repos: %v", err)
 	}
 	u.NumRepos++
 
 	// Give access to all members in teams with access to all repositories.
 	if u.IsOrganization() {
-		if err := u.loadTeams(ctx.e); err != nil {
+		if err := u.loadTeams(ctx.Engine()); err != nil {
 			return fmt.Errorf("loadTeams: %v", err)
 		}
 		for _, t := range u.Teams {
 			if t.IncludesAllRepositories {
-				if err := t.addRepository(ctx.e, repo); err != nil {
+				if err := t.addRepository(ctx.Engine(), repo); err != nil {
 					return fmt.Errorf("addRepository: %v", err)
 				}
 			}
 		}
 
-		if isAdmin, err := isUserRepoAdmin(ctx.e, repo, doer); err != nil {
+		if isAdmin, err := isUserRepoAdmin(ctx.Engine(), repo, doer); err != nil {
 			return fmt.Errorf("isUserRepoAdmin: %v", err)
 		} else if !isAdmin {
 			// Make creator repo admin if it wan't assigned automatically
-			if err = repo.addCollaborator(ctx.e, doer); err != nil {
+			if err = repo.addCollaborator(ctx.Engine(), doer); err != nil {
 				return fmt.Errorf("AddCollaborator: %v", err)
 			}
-			if err = repo.changeCollaborationAccessMode(ctx.e, doer.ID, AccessModeAdmin); err != nil {
+			if err = repo.changeCollaborationAccessMode(ctx.Engine(), doer.ID, AccessModeAdmin); err != nil {
 				return fmt.Errorf("ChangeCollaborationAccessMode: %v", err)
 			}
 		}
-	} else if err = repo.recalculateAccesses(ctx.e); err != nil {
+	} else if err = repo.recalculateAccesses(ctx.Engine()); err != nil {
 		// Organization automatically called this in addRepository method.
 		return fmt.Errorf("recalculateAccesses: %v", err)
 	}
@@ -1155,12 +1160,12 @@ func CreateRepository(ctx DBContext, doer, u *User, repo *Repository, overwriteO
 	}
 
 	if setting.Service.AutoWatchNewRepos {
-		if err = watchRepo(ctx.e, doer.ID, repo.ID, true); err != nil {
+		if err = watchRepo(ctx.Engine(), doer.ID, repo.ID, true); err != nil {
 			return fmt.Errorf("watchRepo: %v", err)
 		}
 	}
 
-	if err = copyDefaultWebhooksToRepo(ctx.e, repo.ID); err != nil {
+	if err = copyDefaultWebhooksToRepo(ctx.Engine(), repo.ID); err != nil {
 		return fmt.Errorf("copyDefaultWebhooksToRepo: %v", err)
 	}
 
@@ -1168,7 +1173,7 @@ func CreateRepository(ctx DBContext, doer, u *User, repo *Repository, overwriteO
 }
 
 func countRepositories(userID int64, private bool) int64 {
-	sess := x.Where("id > 0")
+	sess := db.DefaultContext().Engine().Where("id > 0")
 
 	if userID > 0 {
 		sess.And("owner_id = ?", userID)
@@ -1204,14 +1209,14 @@ func RepoPath(userName, repoName string) string {
 }
 
 // IncrementRepoForkNum increment repository fork number
-func IncrementRepoForkNum(ctx DBContext, repoID int64) error {
-	_, err := ctx.e.Exec("UPDATE `repository` SET num_forks=num_forks+1 WHERE id=?", repoID)
+func IncrementRepoForkNum(ctx *db.Context, repoID int64) error {
+	_, err := ctx.Engine().Exec("UPDATE `repository` SET num_forks=num_forks+1 WHERE id=?", repoID)
 	return err
 }
 
 // DecrementRepoForkNum decrement repository fork number
-func DecrementRepoForkNum(ctx DBContext, repoID int64) error {
-	_, err := ctx.e.Exec("UPDATE `repository` SET num_forks=num_forks-1 WHERE id=?", repoID)
+func DecrementRepoForkNum(ctx *db.Context, repoID int64) error {
+	_, err := ctx.Engine().Exec("UPDATE `repository` SET num_forks=num_forks-1 WHERE id=?", repoID)
 	return err
 }
 
@@ -1251,7 +1256,7 @@ func ChangeRepositoryName(doer *User, repo *Repository, newRepoName string) (err
 		}
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return fmt.Errorf("sess.Begin: %v", err)
@@ -1264,7 +1269,7 @@ func ChangeRepositoryName(doer *User, repo *Repository, newRepoName string) (err
 	return sess.Commit()
 }
 
-func getRepositoriesByForkID(e Engine, forkID int64) ([]*Repository, error) {
+func getRepositoriesByForkID(e db.Engine, forkID int64) ([]*Repository, error) {
 	repos := make([]*Repository, 0, 10)
 	return repos, e.
 		Where("fork_id=?", forkID).
@@ -1273,10 +1278,10 @@ func getRepositoriesByForkID(e Engine, forkID int64) ([]*Repository, error) {
 
 // GetRepositoriesByForkID returns all repositories with given fork ID.
 func GetRepositoriesByForkID(forkID int64) ([]*Repository, error) {
-	return getRepositoriesByForkID(x, forkID)
+	return getRepositoriesByForkID(db.DefaultContext().Engine(), forkID)
 }
 
-func updateRepository(e Engine, repo *Repository, visibilityChanged bool) (err error) {
+func updateRepository(e db.Engine, repo *Repository, visibilityChanged bool) (err error) {
 	repo.LowerName = strings.ToLower(repo.Name)
 
 	if utf8.RuneCountInString(repo.Description) > 255 {
@@ -1351,13 +1356,13 @@ func updateRepository(e Engine, repo *Repository, visibilityChanged bool) (err e
 }
 
 // UpdateRepositoryCtx updates a repository with db context
-func UpdateRepositoryCtx(ctx DBContext, repo *Repository, visibilityChanged bool) error {
-	return updateRepository(ctx.e, repo, visibilityChanged)
+func UpdateRepositoryCtx(ctx *db.Context, repo *Repository, visibilityChanged bool) error {
+	return updateRepository(ctx.Engine(), repo, visibilityChanged)
 }
 
 // UpdateRepository updates a repository
 func UpdateRepository(repo *Repository, visibilityChanged bool) (err error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -1375,7 +1380,7 @@ func UpdateRepositoryOwnerNames(ownerID int64, ownerName string) error {
 	if ownerID == 0 {
 		return nil
 	}
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -1392,13 +1397,13 @@ func UpdateRepositoryOwnerNames(ownerID int64, ownerName string) error {
 
 // UpdateRepositoryUpdatedTime updates a repository's updated time
 func UpdateRepositoryUpdatedTime(repoID int64, updateTime time.Time) error {
-	_, err := x.Exec("UPDATE repository SET updated_unix = ? WHERE id = ?", updateTime.Unix(), repoID)
+	_, err := db.DefaultContext().Engine().Exec("UPDATE repository SET updated_unix = ? WHERE id = ?", updateTime.Unix(), repoID)
 	return err
 }
 
 // UpdateRepositoryUnits updates a repository's units
 func UpdateRepositoryUnits(repo *Repository, units []RepoUnit, deleteUnitTypes []UnitType) (err error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -1425,7 +1430,7 @@ func UpdateRepositoryUnits(repo *Repository, units []RepoUnit, deleteUnitTypes [
 // DeleteRepository deletes a repository for a user or organization.
 // make sure if you call this func to close open sessions (sqlite will otherwise get a deadlock)
 func DeleteRepository(doer *User, uid, repoID int64) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -1533,7 +1538,7 @@ func DeleteRepository(doer *User, uid, repoID int64) error {
 	}
 
 	// Delete issue index
-	if err := deleteResouceIndex(sess, "issue_index", repoID); err != nil {
+	if err := db.DeleteResouceIndex(sess, "issue_index", repoID); err != nil {
 		return err
 	}
 
@@ -1641,21 +1646,21 @@ func DeleteRepository(doer *User, uid, repoID int64) error {
 
 	// Remove repository files.
 	repoPath := repo.RepoPath()
-	removeAllWithNotice(x, "Delete repository files", repoPath)
+	removeAllWithNotice(db.DefaultContext().Engine(), "Delete repository files", repoPath)
 
 	// Remove wiki files
 	if repo.HasWiki() {
-		removeAllWithNotice(x, "Delete repository wiki", repo.WikiPath())
+		removeAllWithNotice(db.DefaultContext().Engine(), "Delete repository wiki", repo.WikiPath())
 	}
 
 	// Remove archives
 	for i := range archivePaths {
-		removeStorageWithNotice(x, storage.RepoArchives, "Delete repo archive file", archivePaths[i])
+		removeStorageWithNotice(db.DefaultContext().Engine(), storage.RepoArchives, "Delete repo archive file", archivePaths[i])
 	}
 
 	// Remove lfs objects
 	for i := range lfsPaths {
-		removeStorageWithNotice(x, storage.LFS, "Delete orphaned LFS file", lfsPaths[i])
+		removeStorageWithNotice(db.DefaultContext().Engine(), storage.LFS, "Delete orphaned LFS file", lfsPaths[i])
 	}
 
 	// Remove issue attachment files.
@@ -1684,10 +1689,10 @@ func DeleteRepository(doer *User, uid, repoID int64) error {
 
 // GetRepositoryByOwnerAndName returns the repository by given ownername and reponame.
 func GetRepositoryByOwnerAndName(ownerName, repoName string) (*Repository, error) {
-	return getRepositoryByOwnerAndName(x, ownerName, repoName)
+	return getRepositoryByOwnerAndName(db.DefaultContext().Engine(), ownerName, repoName)
 }
 
-func getRepositoryByOwnerAndName(e Engine, ownerName, repoName string) (*Repository, error) {
+func getRepositoryByOwnerAndName(e db.Engine, ownerName, repoName string) (*Repository, error) {
 	var repo Repository
 	has, err := e.Table("repository").Select("repository.*").
 		Join("INNER", "`user`", "`user`.id = repository.owner_id").
@@ -1708,7 +1713,7 @@ func GetRepositoryByName(ownerID int64, name string) (*Repository, error) {
 		OwnerID:   ownerID,
 		LowerName: strings.ToLower(name),
 	}
-	has, err := x.Get(repo)
+	has, err := db.DefaultContext().Engine().Get(repo)
 	if err != nil {
 		return nil, err
 	} else if !has {
@@ -1717,7 +1722,7 @@ func GetRepositoryByName(ownerID int64, name string) (*Repository, error) {
 	return repo, err
 }
 
-func getRepositoryByID(e Engine, id int64) (*Repository, error) {
+func getRepositoryByID(e db.Engine, id int64) (*Repository, error) {
 	repo := new(Repository)
 	has, err := e.ID(id).Get(repo)
 	if err != nil {
@@ -1730,18 +1735,18 @@ func getRepositoryByID(e Engine, id int64) (*Repository, error) {
 
 // GetRepositoryByID returns the repository by given id if exists.
 func GetRepositoryByID(id int64) (*Repository, error) {
-	return getRepositoryByID(x, id)
+	return getRepositoryByID(db.DefaultContext().Engine(), id)
 }
 
 // GetRepositoryByIDCtx returns the repository by given id if exists.
-func GetRepositoryByIDCtx(ctx DBContext, id int64) (*Repository, error) {
-	return getRepositoryByID(ctx.e, id)
+func GetRepositoryByIDCtx(ctx *db.Context, id int64) (*Repository, error) {
+	return getRepositoryByID(ctx.Engine(), id)
 }
 
 // GetRepositoriesMapByIDs returns the repositories by given id slice.
 func GetRepositoriesMapByIDs(ids []int64) (map[int64]*Repository, error) {
 	repos := make(map[int64]*Repository, len(ids))
-	return repos, x.In("id", ids).Find(&repos)
+	return repos, db.DefaultContext().Engine().In("id", ids).Find(&repos)
 }
 
 // GetUserRepositories returns a list of repositories of given user.
@@ -1760,7 +1765,7 @@ func GetUserRepositories(opts *SearchRepoOptions) ([]*Repository, int64, error)
 		cond = cond.And(builder.In("lower_name", opts.LowerNames))
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	count, err := sess.Where(cond).Count(new(Repository))
@@ -1776,37 +1781,37 @@ func GetUserRepositories(opts *SearchRepoOptions) ([]*Repository, int64, error)
 // GetUserMirrorRepositories returns a list of mirror repositories of given user.
 func GetUserMirrorRepositories(userID int64) ([]*Repository, error) {
 	repos := make([]*Repository, 0, 10)
-	return repos, x.
+	return repos, db.DefaultContext().Engine().
 		Where("owner_id = ?", userID).
 		And("is_mirror = ?", true).
 		Find(&repos)
 }
 
-func getRepositoryCount(e Engine, u *User) (int64, error) {
+func getRepositoryCount(e db.Engine, u *User) (int64, error) {
 	return e.Count(&Repository{OwnerID: u.ID})
 }
 
-func getPublicRepositoryCount(e Engine, u *User) (int64, error) {
+func getPublicRepositoryCount(e db.Engine, u *User) (int64, error) {
 	return e.Where("is_private = ?", false).Count(&Repository{OwnerID: u.ID})
 }
 
-func getPrivateRepositoryCount(e Engine, u *User) (int64, error) {
+func getPrivateRepositoryCount(e db.Engine, u *User) (int64, error) {
 	return e.Where("is_private = ?", true).Count(&Repository{OwnerID: u.ID})
 }
 
 // GetRepositoryCount returns the total number of repositories of user.
 func GetRepositoryCount(u *User) (int64, error) {
-	return getRepositoryCount(x, u)
+	return getRepositoryCount(db.DefaultContext().Engine(), u)
 }
 
 // GetPublicRepositoryCount returns the total number of public repositories of user.
 func GetPublicRepositoryCount(u *User) (int64, error) {
-	return getPublicRepositoryCount(x, u)
+	return getPublicRepositoryCount(db.DefaultContext().Engine(), u)
 }
 
 // GetPrivateRepositoryCount returns the total number of private repositories of user.
 func GetPrivateRepositoryCount(u *User) (int64, error) {
-	return getPrivateRepositoryCount(x, u)
+	return getPrivateRepositoryCount(db.DefaultContext().Engine(), u)
 }
 
 // DeleteOldRepositoryArchives deletes old repository archives.
@@ -1815,7 +1820,7 @@ func DeleteOldRepositoryArchives(ctx context.Context, olderThan time.Duration) e
 
 	for {
 		var archivers []RepoArchiver
-		err := x.Where("created_unix < ?", time.Now().Add(-olderThan).Unix()).
+		err := db.DefaultContext().Engine().Where("created_unix < ?", time.Now().Add(-olderThan).Unix()).
 			Asc("created_unix").
 			Limit(100).
 			Find(&archivers)
@@ -1845,7 +1850,7 @@ func deleteOldRepoArchiver(ctx context.Context, archiver *RepoArchiver) error {
 	if err != nil {
 		return err
 	}
-	_, err = x.ID(archiver.ID).Delete(delRepoArchiver)
+	_, err = db.DefaultContext().Engine().ID(archiver.ID).Delete(delRepoArchiver)
 	if err != nil {
 		return err
 	}
@@ -1861,7 +1866,7 @@ type repoChecker struct {
 }
 
 func repoStatsCheck(ctx context.Context, checker *repoChecker) {
-	results, err := x.Query(checker.querySQL)
+	results, err := db.DefaultContext().Engine().Query(checker.querySQL)
 	if err != nil {
 		log.Error("Select %s: %v", checker.desc, err)
 		return
@@ -1875,7 +1880,7 @@ func repoStatsCheck(ctx context.Context, checker *repoChecker) {
 		default:
 		}
 		log.Trace("Updating %s: %d", checker.desc, id)
-		_, err = x.Exec(checker.correctSQL, id, id)
+		_, err = db.DefaultContext().Engine().Exec(checker.correctSQL, id, id)
 		if err != nil {
 			log.Error("Update %s[%d]: %v", checker.desc, id, err)
 		}
@@ -1930,7 +1935,7 @@ func CheckRepoStats(ctx context.Context) error {
 
 	// ***** START: Repository.NumClosedIssues *****
 	desc := "repository count 'num_closed_issues'"
-	results, err := x.Query("SELECT repo.id FROM `repository` repo WHERE repo.num_closed_issues!=(SELECT COUNT(*) FROM `issue` WHERE repo_id=repo.id AND is_closed=? AND is_pull=?)", true, false)
+	results, err := db.DefaultContext().Engine().Query("SELECT repo.id FROM `repository` repo WHERE repo.num_closed_issues!=(SELECT COUNT(*) FROM `issue` WHERE repo_id=repo.id AND is_closed=? AND is_pull=?)", true, false)
 	if err != nil {
 		log.Error("Select %s: %v", desc, err)
 	} else {
@@ -1943,7 +1948,7 @@ func CheckRepoStats(ctx context.Context) error {
 			default:
 			}
 			log.Trace("Updating %s: %d", desc, id)
-			_, err = x.Exec("UPDATE `repository` SET num_closed_issues=(SELECT COUNT(*) FROM `issue` WHERE repo_id=? AND is_closed=? AND is_pull=?) WHERE id=?", id, true, false, id)
+			_, err = db.DefaultContext().Engine().Exec("UPDATE `repository` SET num_closed_issues=(SELECT COUNT(*) FROM `issue` WHERE repo_id=? AND is_closed=? AND is_pull=?) WHERE id=?", id, true, false, id)
 			if err != nil {
 				log.Error("Update %s[%d]: %v", desc, id, err)
 			}
@@ -1953,7 +1958,7 @@ func CheckRepoStats(ctx context.Context) error {
 
 	// ***** START: Repository.NumClosedPulls *****
 	desc = "repository count 'num_closed_pulls'"
-	results, err = x.Query("SELECT repo.id FROM `repository` repo WHERE repo.num_closed_pulls!=(SELECT COUNT(*) FROM `issue` WHERE repo_id=repo.id AND is_closed=? AND is_pull=?)", true, true)
+	results, err = db.DefaultContext().Engine().Query("SELECT repo.id FROM `repository` repo WHERE repo.num_closed_pulls!=(SELECT COUNT(*) FROM `issue` WHERE repo_id=repo.id AND is_closed=? AND is_pull=?)", true, true)
 	if err != nil {
 		log.Error("Select %s: %v", desc, err)
 	} else {
@@ -1966,7 +1971,7 @@ func CheckRepoStats(ctx context.Context) error {
 			default:
 			}
 			log.Trace("Updating %s: %d", desc, id)
-			_, err = x.Exec("UPDATE `repository` SET num_closed_pulls=(SELECT COUNT(*) FROM `issue` WHERE repo_id=? AND is_closed=? AND is_pull=?) WHERE id=?", id, true, true, id)
+			_, err = db.DefaultContext().Engine().Exec("UPDATE `repository` SET num_closed_pulls=(SELECT COUNT(*) FROM `issue` WHERE repo_id=? AND is_closed=? AND is_pull=?) WHERE id=?", id, true, true, id)
 			if err != nil {
 				log.Error("Update %s[%d]: %v", desc, id, err)
 			}
@@ -1976,7 +1981,7 @@ func CheckRepoStats(ctx context.Context) error {
 
 	// FIXME: use checker when stop supporting old fork repo format.
 	// ***** START: Repository.NumForks *****
-	results, err = x.Query("SELECT repo.id FROM `repository` repo WHERE repo.num_forks!=(SELECT COUNT(*) FROM `repository` WHERE fork_id=repo.id)")
+	results, err = db.DefaultContext().Engine().Query("SELECT repo.id FROM `repository` repo WHERE repo.num_forks!=(SELECT COUNT(*) FROM `repository` WHERE fork_id=repo.id)")
 	if err != nil {
 		log.Error("Select repository count 'num_forks': %v", err)
 	} else {
@@ -1996,7 +2001,7 @@ func CheckRepoStats(ctx context.Context) error {
 				continue
 			}
 
-			rawResult, err := x.Query("SELECT COUNT(*) FROM `repository` WHERE fork_id=?", repo.ID)
+			rawResult, err := db.DefaultContext().Engine().Query("SELECT COUNT(*) FROM `repository` WHERE fork_id=?", repo.ID)
 			if err != nil {
 				log.Error("Select count of forks[%d]: %v", repo.ID, err)
 				continue
@@ -2016,7 +2021,7 @@ func CheckRepoStats(ctx context.Context) error {
 // SetArchiveRepoState sets if a repo is archived
 func (repo *Repository) SetArchiveRepoState(isArchived bool) (err error) {
 	repo.IsArchived = isArchived
-	_, err = x.Where("id = ?", repo.ID).Cols("is_archived").NoAutoTime().Update(repo)
+	_, err = db.DefaultContext().Engine().Where("id = ?", repo.ID).Cols("is_archived").NoAutoTime().Update(repo)
 	return
 }
 
@@ -2030,23 +2035,23 @@ func (repo *Repository) SetArchiveRepoState(isArchived bool) (err error) {
 // HasForkedRepo checks if given user has already forked a repository with given ID.
 func HasForkedRepo(ownerID, repoID int64) (*Repository, bool) {
 	repo := new(Repository)
-	has, _ := x.
+	has, _ := db.DefaultContext().Engine().
 		Where("owner_id=? AND fork_id=?", ownerID, repoID).
 		Get(repo)
 	return repo, has
 }
 
 // CopyLFS copies LFS data from one repo to another
-func CopyLFS(ctx DBContext, newRepo, oldRepo *Repository) error {
+func CopyLFS(ctx *db.Context, newRepo, oldRepo *Repository) error {
 	var lfsObjects []*LFSMetaObject
-	if err := ctx.e.Where("repository_id=?", oldRepo.ID).Find(&lfsObjects); err != nil {
+	if err := ctx.Engine().Where("repository_id=?", oldRepo.ID).Find(&lfsObjects); err != nil {
 		return err
 	}
 
 	for _, v := range lfsObjects {
 		v.ID = 0
 		v.RepositoryID = newRepo.ID
-		if _, err := ctx.e.Insert(v); err != nil {
+		if _, err := ctx.Engine().Insert(v); err != nil {
 			return err
 		}
 	}
@@ -2058,7 +2063,7 @@ func CopyLFS(ctx DBContext, newRepo, oldRepo *Repository) error {
 func (repo *Repository) GetForks(listOptions ListOptions) ([]*Repository, error) {
 	if listOptions.Page == 0 {
 		forks := make([]*Repository, 0, repo.NumForks)
-		return forks, x.Find(&forks, &Repository{ForkID: repo.ID})
+		return forks, db.DefaultContext().Engine().Find(&forks, &Repository{ForkID: repo.ID})
 	}
 
 	sess := getPaginatedSession(&listOptions)
@@ -2069,7 +2074,7 @@ func (repo *Repository) GetForks(listOptions ListOptions) ([]*Repository, error)
 // GetUserFork return user forked repository from this repository, if not forked return nil
 func (repo *Repository) GetUserFork(userID int64) (*Repository, error) {
 	var forkedRepo Repository
-	has, err := x.Where("fork_id = ?", repo.ID).And("owner_id = ?", userID).Get(&forkedRepo)
+	has, err := db.DefaultContext().Engine().Where("fork_id = ?", repo.ID).And("owner_id = ?", userID).Get(&forkedRepo)
 	if err != nil {
 		return nil, err
 	}
@@ -2105,14 +2110,14 @@ func (repo *Repository) GetTreePathLock(treePath string) (*LFSLock, error) {
 	return nil, nil
 }
 
-func updateRepositoryCols(e Engine, repo *Repository, cols ...string) error {
+func updateRepositoryCols(e db.Engine, repo *Repository, cols ...string) error {
 	_, err := e.ID(repo.ID).Cols(cols...).Update(repo)
 	return err
 }
 
 // UpdateRepositoryCols updates repository's columns
 func UpdateRepositoryCols(repo *Repository, cols ...string) error {
-	return updateRepositoryCols(x, repo, cols...)
+	return updateRepositoryCols(db.DefaultContext().Engine(), repo, cols...)
 }
 
 // GetTrustModel will get the TrustModel for the repo or the default trust model
@@ -2130,7 +2135,7 @@ func (repo *Repository) GetTrustModel() TrustModelType {
 // DoctorUserStarNum recalculate Stars number for all user
 func DoctorUserStarNum() (err error) {
 	const batchSize = 100
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	for start := 0; ; start += batchSize {
@@ -2168,7 +2173,7 @@ func IterateRepository(f func(repo *Repository) error) error {
 	batchSize := setting.Database.IterateBufferSize
 	for {
 		repos := make([]*Repository, 0, batchSize)
-		if err := x.Limit(batchSize, start).Find(&repos); err != nil {
+		if err := db.DefaultContext().Engine().Limit(batchSize, start).Find(&repos); err != nil {
 			return err
 		}
 		if len(repos) == 0 {
diff --git a/models/repo_activity.go b/models/repo_activity.go
index 8ee1011c2..cfbda2141 100644
--- a/models/repo_activity.go
+++ b/models/repo_activity.go
@@ -9,6 +9,7 @@ import (
 	"sort"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 
 	"xorm.io/xorm"
@@ -245,7 +246,7 @@ func (stats *ActivityStats) FillPullRequests(repoID int64, fromTime time.Time) e
 }
 
 func pullRequestsForActivityStatement(repoID int64, fromTime time.Time, merged bool) *xorm.Session {
-	sess := x.Where("pull_request.base_repo_id=?", repoID).
+	sess := db.DefaultContext().Engine().Where("pull_request.base_repo_id=?", repoID).
 		Join("INNER", "issue", "pull_request.issue_id = issue.id")
 
 	if merged {
@@ -313,7 +314,7 @@ func (stats *ActivityStats) FillUnresolvedIssues(repoID int64, fromTime time.Tim
 }
 
 func issuesForActivityStatement(repoID int64, fromTime time.Time, closed, unresolved bool) *xorm.Session {
-	sess := x.Where("issue.repo_id = ?", repoID).
+	sess := db.DefaultContext().Engine().Where("issue.repo_id = ?", repoID).
 		And("issue.is_closed = ?", closed)
 
 	if !unresolved {
@@ -355,7 +356,7 @@ func (stats *ActivityStats) FillReleases(repoID int64, fromTime time.Time) error
 }
 
 func releasesForActivityStatement(repoID int64, fromTime time.Time) *xorm.Session {
-	return x.Where("release.repo_id = ?", repoID).
+	return db.DefaultContext().Engine().Where("release.repo_id = ?", repoID).
 		And("release.is_draft = ?", false).
 		And("release.created_unix >= ?", fromTime.Unix())
 }
diff --git a/models/repo_archiver.go b/models/repo_archiver.go
index 677f0d3e8..b268e65e0 100644
--- a/models/repo_archiver.go
+++ b/models/repo_archiver.go
@@ -7,6 +7,7 @@ package models
 import (
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/timeutil"
 )
@@ -31,6 +32,10 @@ type RepoArchiver struct {
 	CreatedUnix timeutil.TimeStamp `xorm:"INDEX NOT NULL created"`
 }
 
+func init() {
+	db.RegisterModel(new(RepoArchiver))
+}
+
 // LoadRepo loads repository
 func (archiver *RepoArchiver) LoadRepo() (*Repository, error) {
 	if archiver.Repo != nil {
@@ -38,7 +43,7 @@ func (archiver *RepoArchiver) LoadRepo() (*Repository, error) {
 	}
 
 	var repo Repository
-	has, err := x.ID(archiver.RepoID).Get(&repo)
+	has, err := db.DefaultContext().Engine().ID(archiver.RepoID).Get(&repo)
 	if err != nil {
 		return nil, err
 	}
@@ -56,9 +61,9 @@ func (archiver *RepoArchiver) RelativePath() (string, error) {
 }
 
 // GetRepoArchiver get an archiver
-func GetRepoArchiver(ctx DBContext, repoID int64, tp git.ArchiveType, commitID string) (*RepoArchiver, error) {
+func GetRepoArchiver(ctx *db.Context, repoID int64, tp git.ArchiveType, commitID string) (*RepoArchiver, error) {
 	var archiver RepoArchiver
-	has, err := ctx.e.Where("repo_id=?", repoID).And("`type`=?", tp).And("commit_id=?", commitID).Get(&archiver)
+	has, err := ctx.Engine().Where("repo_id=?", repoID).And("`type`=?", tp).And("commit_id=?", commitID).Get(&archiver)
 	if err != nil {
 		return nil, err
 	}
@@ -69,19 +74,19 @@ func GetRepoArchiver(ctx DBContext, repoID int64, tp git.ArchiveType, commitID s
 }
 
 // AddRepoArchiver adds an archiver
-func AddRepoArchiver(ctx DBContext, archiver *RepoArchiver) error {
-	_, err := ctx.e.Insert(archiver)
+func AddRepoArchiver(ctx *db.Context, archiver *RepoArchiver) error {
+	_, err := ctx.Engine().Insert(archiver)
 	return err
 }
 
 // UpdateRepoArchiverStatus updates archiver's status
-func UpdateRepoArchiverStatus(ctx DBContext, archiver *RepoArchiver) error {
-	_, err := ctx.e.ID(archiver.ID).Cols("status").Update(archiver)
+func UpdateRepoArchiverStatus(ctx *db.Context, archiver *RepoArchiver) error {
+	_, err := ctx.Engine().ID(archiver.ID).Cols("status").Update(archiver)
 	return err
 }
 
 // DeleteAllRepoArchives deletes all repo archives records
 func DeleteAllRepoArchives() error {
-	_, err := x.Where("1=1").Delete(new(RepoArchiver))
+	_, err := db.DefaultContext().Engine().Where("1=1").Delete(new(RepoArchiver))
 	return err
 }
diff --git a/models/repo_avatar.go b/models/repo_avatar.go
index 6f8f55f9e..8133cdc70 100644
--- a/models/repo_avatar.go
+++ b/models/repo_avatar.go
@@ -13,6 +13,7 @@ import (
 	"strconv"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/avatar"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -25,7 +26,7 @@ func (repo *Repository) CustomAvatarRelativePath() string {
 }
 
 // generateRandomAvatar generates a random avatar for repository.
-func (repo *Repository) generateRandomAvatar(e Engine) error {
+func (repo *Repository) generateRandomAvatar(e db.Engine) error {
 	idToString := fmt.Sprintf("%d", repo.ID)
 
 	seed := idToString
@@ -56,7 +57,7 @@ func (repo *Repository) generateRandomAvatar(e Engine) error {
 
 // RemoveRandomAvatars removes the randomly generated avatars that were created for repositories
 func RemoveRandomAvatars(ctx context.Context) error {
-	return x.
+	return db.DefaultContext().Engine().
 		Where("id > 0").BufferSize(setting.Database.IterateBufferSize).
 		Iterate(new(Repository),
 			func(idx int, bean interface{}) error {
@@ -76,10 +77,10 @@ func RemoveRandomAvatars(ctx context.Context) error {
 
 // RelAvatarLink returns a relative link to the repository's avatar.
 func (repo *Repository) RelAvatarLink() string {
-	return repo.relAvatarLink(x)
+	return repo.relAvatarLink(db.DefaultContext().Engine())
 }
 
-func (repo *Repository) relAvatarLink(e Engine) string {
+func (repo *Repository) relAvatarLink(e db.Engine) string {
 	// If no avatar - path is empty
 	avatarPath := repo.CustomAvatarRelativePath()
 	if len(avatarPath) == 0 {
@@ -100,11 +101,11 @@ func (repo *Repository) relAvatarLink(e Engine) string {
 
 // AvatarLink returns a link to the repository's avatar.
 func (repo *Repository) AvatarLink() string {
-	return repo.avatarLink(x)
+	return repo.avatarLink(db.DefaultContext().Engine())
 }
 
 // avatarLink returns user avatar absolute link.
-func (repo *Repository) avatarLink(e Engine) string {
+func (repo *Repository) avatarLink(e db.Engine) string {
 	link := repo.relAvatarLink(e)
 	// link may be empty!
 	if len(link) > 0 {
@@ -128,7 +129,7 @@ func (repo *Repository) UploadAvatar(data []byte) error {
 		return nil
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -171,7 +172,7 @@ func (repo *Repository) DeleteAvatar() error {
 	avatarPath := repo.CustomAvatarRelativePath()
 	log.Trace("DeleteAvatar[%d]: %s", repo.ID, avatarPath)
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
diff --git a/models/repo_collaboration.go b/models/repo_collaboration.go
index 84e49b2c6..1199a5640 100644
--- a/models/repo_collaboration.go
+++ b/models/repo_collaboration.go
@@ -8,6 +8,7 @@ package models
 import (
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/timeutil"
 
 	"xorm.io/builder"
@@ -23,7 +24,11 @@ type Collaboration struct {
 	UpdatedUnix timeutil.TimeStamp `xorm:"INDEX updated"`
 }
 
-func (repo *Repository) addCollaborator(e Engine, u *User) error {
+func init() {
+	db.RegisterModel(new(Collaboration))
+}
+
+func (repo *Repository) addCollaborator(e db.Engine, u *User) error {
 	collaboration := &Collaboration{
 		RepoID: repo.ID,
 		UserID: u.ID,
@@ -46,7 +51,7 @@ func (repo *Repository) addCollaborator(e Engine, u *User) error {
 
 // AddCollaborator adds new collaboration to a repository with default access mode.
 func (repo *Repository) AddCollaborator(u *User) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -59,7 +64,7 @@ func (repo *Repository) AddCollaborator(u *User) error {
 	return sess.Commit()
 }
 
-func (repo *Repository) getCollaborations(e Engine, listOptions ListOptions) ([]*Collaboration, error) {
+func (repo *Repository) getCollaborations(e db.Engine, listOptions ListOptions) ([]*Collaboration, error) {
 	if listOptions.Page == 0 {
 		collaborations := make([]*Collaboration, 0, 8)
 		return collaborations, e.Find(&collaborations, &Collaboration{RepoID: repo.ID})
@@ -77,7 +82,7 @@ type Collaborator struct {
 	Collaboration *Collaboration
 }
 
-func (repo *Repository) getCollaborators(e Engine, listOptions ListOptions) ([]*Collaborator, error) {
+func (repo *Repository) getCollaborators(e db.Engine, listOptions ListOptions) ([]*Collaborator, error) {
 	collaborations, err := repo.getCollaborations(e, listOptions)
 	if err != nil {
 		return nil, fmt.Errorf("getCollaborations: %v", err)
@@ -99,15 +104,15 @@ func (repo *Repository) getCollaborators(e Engine, listOptions ListOptions) ([]*
 
 // GetCollaborators returns the collaborators for a repository
 func (repo *Repository) GetCollaborators(listOptions ListOptions) ([]*Collaborator, error) {
-	return repo.getCollaborators(x, listOptions)
+	return repo.getCollaborators(db.DefaultContext().Engine(), listOptions)
 }
 
 // CountCollaborators returns total number of collaborators for a repository
 func (repo *Repository) CountCollaborators() (int64, error) {
-	return x.Where("repo_id = ? ", repo.ID).Count(&Collaboration{})
+	return db.DefaultContext().Engine().Where("repo_id = ? ", repo.ID).Count(&Collaboration{})
 }
 
-func (repo *Repository) getCollaboration(e Engine, uid int64) (*Collaboration, error) {
+func (repo *Repository) getCollaboration(e db.Engine, uid int64) (*Collaboration, error) {
 	collaboration := &Collaboration{
 		RepoID: repo.ID,
 		UserID: uid,
@@ -119,16 +124,16 @@ func (repo *Repository) getCollaboration(e Engine, uid int64) (*Collaboration, e
 	return collaboration, err
 }
 
-func (repo *Repository) isCollaborator(e Engine, userID int64) (bool, error) {
+func (repo *Repository) isCollaborator(e db.Engine, userID int64) (bool, error) {
 	return e.Get(&Collaboration{RepoID: repo.ID, UserID: userID})
 }
 
 // IsCollaborator check if a user is a collaborator of a repository
 func (repo *Repository) IsCollaborator(userID int64) (bool, error) {
-	return repo.isCollaborator(x, userID)
+	return repo.isCollaborator(db.DefaultContext().Engine(), userID)
 }
 
-func (repo *Repository) changeCollaborationAccessMode(e Engine, uid int64, mode AccessMode) error {
+func (repo *Repository) changeCollaborationAccessMode(e db.Engine, uid int64, mode AccessMode) error {
 	// Discard invalid input
 	if mode <= AccessModeNone || mode > AccessModeOwner {
 		return nil
@@ -164,7 +169,7 @@ func (repo *Repository) changeCollaborationAccessMode(e Engine, uid int64, mode
 
 // ChangeCollaborationAccessMode sets new access mode for the collaboration.
 func (repo *Repository) ChangeCollaborationAccessMode(uid int64, mode AccessMode) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -184,7 +189,7 @@ func (repo *Repository) DeleteCollaboration(uid int64) (err error) {
 		UserID: uid,
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -212,7 +217,7 @@ func (repo *Repository) DeleteCollaboration(uid int64) (err error) {
 	return sess.Commit()
 }
 
-func (repo *Repository) reconsiderIssueAssignees(e Engine, uid int64) error {
+func (repo *Repository) reconsiderIssueAssignees(e db.Engine, uid int64) error {
 	user, err := getUserByID(e, uid)
 	if err != nil {
 		return err
@@ -230,7 +235,7 @@ func (repo *Repository) reconsiderIssueAssignees(e Engine, uid int64) error {
 	return nil
 }
 
-func (repo *Repository) reconsiderWatches(e Engine, uid int64) error {
+func (repo *Repository) reconsiderWatches(e db.Engine, uid int64) error {
 	if has, err := hasAccess(e, uid, repo); err != nil || has {
 		return err
 	}
@@ -243,7 +248,7 @@ func (repo *Repository) reconsiderWatches(e Engine, uid int64) error {
 	return removeIssueWatchersByRepoID(e, uid, repo.ID)
 }
 
-func (repo *Repository) getRepoTeams(e Engine) (teams []*Team, err error) {
+func (repo *Repository) getRepoTeams(e db.Engine) (teams []*Team, err error) {
 	return teams, e.
 		Join("INNER", "team_repo", "team_repo.team_id = team.id").
 		Where("team.org_id = ?", repo.OwnerID).
@@ -254,7 +259,7 @@ func (repo *Repository) getRepoTeams(e Engine) (teams []*Team, err error) {
 
 // GetRepoTeams gets the list of teams that has access to the repository
 func (repo *Repository) GetRepoTeams() ([]*Team, error) {
-	return repo.getRepoTeams(x)
+	return repo.getRepoTeams(db.DefaultContext().Engine())
 }
 
 // IsOwnerMemberCollaborator checks if a provided user is the owner, a collaborator or a member of a team in a repository
@@ -262,7 +267,7 @@ func (repo *Repository) IsOwnerMemberCollaborator(userID int64) (bool, error) {
 	if repo.OwnerID == userID {
 		return true, nil
 	}
-	teamMember, err := x.Join("INNER", "team_repo", "team_repo.team_id = team_user.team_id").
+	teamMember, err := db.DefaultContext().Engine().Join("INNER", "team_repo", "team_repo.team_id = team_user.team_id").
 		Join("INNER", "team_unit", "team_unit.team_id = team_user.team_id").
 		Where("team_repo.repo_id = ?", repo.ID).
 		And("team_unit.`type` = ?", UnitTypeCode).
@@ -274,5 +279,5 @@ func (repo *Repository) IsOwnerMemberCollaborator(userID int64) (bool, error) {
 		return true, nil
 	}
 
-	return x.Get(&Collaboration{RepoID: repo.ID, UserID: userID})
+	return db.DefaultContext().Engine().Get(&Collaboration{RepoID: repo.ID, UserID: userID})
 }
diff --git a/models/repo_collaboration_test.go b/models/repo_collaboration_test.go
index 7bae27bce..32dd2ef5a 100644
--- a/models/repo_collaboration_test.go
+++ b/models/repo_collaboration_test.go
@@ -7,16 +7,17 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestRepository_AddCollaborator(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	testSuccess := func(repoID, userID int64) {
-		repo := AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
+		repo := db.AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
 		assert.NoError(t, repo.GetOwner())
-		user := AssertExistsAndLoadBean(t, &User{ID: userID}).(*User)
+		user := db.AssertExistsAndLoadBean(t, &User{ID: userID}).(*User)
 		assert.NoError(t, repo.AddCollaborator(user))
 		CheckConsistencyFor(t, &Repository{ID: repoID}, &User{ID: userID})
 	}
@@ -26,12 +27,12 @@ func TestRepository_AddCollaborator(t *testing.T) {
 }
 
 func TestRepository_GetCollaborators(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	test := func(repoID int64) {
-		repo := AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
+		repo := db.AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
 		collaborators, err := repo.GetCollaborators(ListOptions{})
 		assert.NoError(t, err)
-		expectedLen, err := x.Count(&Collaboration{RepoID: repoID})
+		expectedLen, err := db.DefaultContext().Engine().Count(&Collaboration{RepoID: repoID})
 		assert.NoError(t, err)
 		assert.Len(t, collaborators, int(expectedLen))
 		for _, collaborator := range collaborators {
@@ -46,49 +47,49 @@ func TestRepository_GetCollaborators(t *testing.T) {
 }
 
 func TestRepository_IsCollaborator(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	test := func(repoID, userID int64, expected bool) {
-		repo := AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
+		repo := db.AssertExistsAndLoadBean(t, &Repository{ID: repoID}).(*Repository)
 		actual, err := repo.IsCollaborator(userID)
 		assert.NoError(t, err)
 		assert.Equal(t, expected, actual)
 	}
 	test(3, 2, true)
-	test(3, NonexistentID, false)
+	test(3, db.NonexistentID, false)
 	test(4, 2, false)
 	test(4, 4, true)
 }
 
 func TestRepository_ChangeCollaborationAccessMode(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 4}).(*Repository)
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 4}).(*Repository)
 	assert.NoError(t, repo.ChangeCollaborationAccessMode(4, AccessModeAdmin))
 
-	collaboration := AssertExistsAndLoadBean(t, &Collaboration{RepoID: repo.ID, UserID: 4}).(*Collaboration)
+	collaboration := db.AssertExistsAndLoadBean(t, &Collaboration{RepoID: repo.ID, UserID: 4}).(*Collaboration)
 	assert.EqualValues(t, AccessModeAdmin, collaboration.Mode)
 
-	access := AssertExistsAndLoadBean(t, &Access{UserID: 4, RepoID: repo.ID}).(*Access)
+	access := db.AssertExistsAndLoadBean(t, &Access{UserID: 4, RepoID: repo.ID}).(*Access)
 	assert.EqualValues(t, AccessModeAdmin, access.Mode)
 
 	assert.NoError(t, repo.ChangeCollaborationAccessMode(4, AccessModeAdmin))
 
-	assert.NoError(t, repo.ChangeCollaborationAccessMode(NonexistentID, AccessModeAdmin))
+	assert.NoError(t, repo.ChangeCollaborationAccessMode(db.NonexistentID, AccessModeAdmin))
 
 	CheckConsistencyFor(t, &Repository{ID: repo.ID})
 }
 
 func TestRepository_DeleteCollaboration(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 4}).(*Repository)
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 4}).(*Repository)
 	assert.NoError(t, repo.GetOwner())
 	assert.NoError(t, repo.DeleteCollaboration(4))
-	AssertNotExistsBean(t, &Collaboration{RepoID: repo.ID, UserID: 4})
+	db.AssertNotExistsBean(t, &Collaboration{RepoID: repo.ID, UserID: 4})
 
 	assert.NoError(t, repo.DeleteCollaboration(4))
-	AssertNotExistsBean(t, &Collaboration{RepoID: repo.ID, UserID: 4})
+	db.AssertNotExistsBean(t, &Collaboration{RepoID: repo.ID, UserID: 4})
 
 	CheckConsistencyFor(t, &Repository{ID: repo.ID})
 }
diff --git a/models/repo_generate.go b/models/repo_generate.go
index 66682903f..e5f5c7e7f 100644
--- a/models/repo_generate.go
+++ b/models/repo_generate.go
@@ -10,6 +10,7 @@ import (
 	"strconv"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/storage"
@@ -67,9 +68,9 @@ func (gt GiteaTemplate) Globs() []glob.Glob {
 }
 
 // GenerateTopics generates topics from a template repository
-func GenerateTopics(ctx DBContext, templateRepo, generateRepo *Repository) error {
+func GenerateTopics(ctx *db.Context, templateRepo, generateRepo *Repository) error {
 	for _, topic := range templateRepo.Topics {
-		if _, err := addTopicByNameToRepo(ctx.e, generateRepo.ID, topic); err != nil {
+		if _, err := addTopicByNameToRepo(ctx.Engine(), generateRepo.ID, topic); err != nil {
 			return err
 		}
 	}
@@ -77,7 +78,7 @@ func GenerateTopics(ctx DBContext, templateRepo, generateRepo *Repository) error
 }
 
 // GenerateGitHooks generates git hooks from a template repository
-func GenerateGitHooks(ctx DBContext, templateRepo, generateRepo *Repository) error {
+func GenerateGitHooks(ctx *db.Context, templateRepo, generateRepo *Repository) error {
 	generateGitRepo, err := git.OpenRepository(generateRepo.RepoPath())
 	if err != nil {
 		return err
@@ -110,7 +111,7 @@ func GenerateGitHooks(ctx DBContext, templateRepo, generateRepo *Repository) err
 }
 
 // GenerateWebhooks generates webhooks from a template repository
-func GenerateWebhooks(ctx DBContext, templateRepo, generateRepo *Repository) error {
+func GenerateWebhooks(ctx *db.Context, templateRepo, generateRepo *Repository) error {
 	templateWebhooks, err := ListWebhooksByOpts(&ListWebhookOptions{RepoID: templateRepo.ID})
 	if err != nil {
 		return err
@@ -130,7 +131,7 @@ func GenerateWebhooks(ctx DBContext, templateRepo, generateRepo *Repository) err
 			Events:      templateWebhook.Events,
 			Meta:        templateWebhook.Meta,
 		}
-		if err := createWebhook(ctx.e, generateWebhook); err != nil {
+		if err := createWebhook(ctx.Engine(), generateWebhook); err != nil {
 			return err
 		}
 	}
@@ -138,18 +139,18 @@ func GenerateWebhooks(ctx DBContext, templateRepo, generateRepo *Repository) err
 }
 
 // GenerateAvatar generates the avatar from a template repository
-func GenerateAvatar(ctx DBContext, templateRepo, generateRepo *Repository) error {
+func GenerateAvatar(ctx *db.Context, templateRepo, generateRepo *Repository) error {
 	generateRepo.Avatar = strings.Replace(templateRepo.Avatar, strconv.FormatInt(templateRepo.ID, 10), strconv.FormatInt(generateRepo.ID, 10), 1)
 	if _, err := storage.Copy(storage.RepoAvatars, generateRepo.CustomAvatarRelativePath(), storage.RepoAvatars, templateRepo.CustomAvatarRelativePath()); err != nil {
 		return err
 	}
 
-	return updateRepositoryCols(ctx.e, generateRepo, "avatar")
+	return updateRepositoryCols(ctx.Engine(), generateRepo, "avatar")
 }
 
 // GenerateIssueLabels generates issue labels from a template repository
-func GenerateIssueLabels(ctx DBContext, templateRepo, generateRepo *Repository) error {
-	templateLabels, err := getLabelsByRepoID(ctx.e, templateRepo.ID, "", ListOptions{})
+func GenerateIssueLabels(ctx *db.Context, templateRepo, generateRepo *Repository) error {
+	templateLabels, err := getLabelsByRepoID(ctx.Engine(), templateRepo.ID, "", ListOptions{})
 	if err != nil {
 		return err
 	}
@@ -161,7 +162,7 @@ func GenerateIssueLabels(ctx DBContext, templateRepo, generateRepo *Repository)
 			Description: templateLabel.Description,
 			Color:       templateLabel.Color,
 		}
-		if err := newLabel(ctx.e, generateLabel); err != nil {
+		if err := newLabel(ctx.Engine(), generateLabel); err != nil {
 			return err
 		}
 	}
diff --git a/models/repo_indexer.go b/models/repo_indexer.go
index de3358f55..4d3d18cac 100644
--- a/models/repo_indexer.go
+++ b/models/repo_indexer.go
@@ -7,6 +7,7 @@ package models
 import (
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"xorm.io/builder"
 )
 
@@ -29,6 +30,10 @@ type RepoIndexerStatus struct {
 	IndexerType RepoIndexerType `xorm:"INDEX(s) NOT NULL DEFAULT 0"`
 }
 
+func init() {
+	db.RegisterModel(new(RepoIndexerStatus))
+}
+
 // GetUnindexedRepos returns repos which do not have an indexer status
 func GetUnindexedRepos(indexerType RepoIndexerType, maxRepoID int64, page, pageSize int) ([]int64, error) {
 	ids := make([]int64, 0, 50)
@@ -37,7 +42,7 @@ func GetUnindexedRepos(indexerType RepoIndexerType, maxRepoID int64, page, pageS
 	}).And(builder.Eq{
 		"repository.is_empty": false,
 	})
-	sess := x.Table("repository").Join("LEFT OUTER", "repo_indexer_status", "repository.id = repo_indexer_status.repo_id AND repo_indexer_status.indexer_type = ?", indexerType)
+	sess := db.DefaultContext().Engine().Table("repository").Join("LEFT OUTER", "repo_indexer_status", "repository.id = repo_indexer_status.repo_id AND repo_indexer_status.indexer_type = ?", indexerType)
 	if maxRepoID > 0 {
 		cond = builder.And(cond, builder.Lte{
 			"repository.id": maxRepoID,
@@ -57,7 +62,7 @@ func GetUnindexedRepos(indexerType RepoIndexerType, maxRepoID int64, page, pageS
 }
 
 // getIndexerStatus loads repo codes indxer status
-func (repo *Repository) getIndexerStatus(e Engine, indexerType RepoIndexerType) (*RepoIndexerStatus, error) {
+func (repo *Repository) getIndexerStatus(e db.Engine, indexerType RepoIndexerType) (*RepoIndexerStatus, error) {
 	switch indexerType {
 	case RepoIndexerTypeCode:
 		if repo.CodeIndexerStatus != nil {
@@ -86,11 +91,11 @@ func (repo *Repository) getIndexerStatus(e Engine, indexerType RepoIndexerType)
 
 // GetIndexerStatus loads repo codes indxer status
 func (repo *Repository) GetIndexerStatus(indexerType RepoIndexerType) (*RepoIndexerStatus, error) {
-	return repo.getIndexerStatus(x, indexerType)
+	return repo.getIndexerStatus(db.DefaultContext().Engine(), indexerType)
 }
 
 // updateIndexerStatus updates indexer status
-func (repo *Repository) updateIndexerStatus(e Engine, indexerType RepoIndexerType, sha string) error {
+func (repo *Repository) updateIndexerStatus(e db.Engine, indexerType RepoIndexerType, sha string) error {
 	status, err := repo.getIndexerStatus(e, indexerType)
 	if err != nil {
 		return fmt.Errorf("UpdateIndexerStatus: Unable to getIndexerStatus for repo: %s Error: %v", repo.FullName(), err)
@@ -115,5 +120,5 @@ func (repo *Repository) updateIndexerStatus(e Engine, indexerType RepoIndexerTyp
 
 // UpdateIndexerStatus updates indexer status
 func (repo *Repository) UpdateIndexerStatus(indexerType RepoIndexerType, sha string) error {
-	return repo.updateIndexerStatus(x, indexerType, sha)
+	return repo.updateIndexerStatus(db.DefaultContext().Engine(), indexerType, sha)
 }
diff --git a/models/repo_language_stats.go b/models/repo_language_stats.go
index 8760726ae..c7af7dc9b 100644
--- a/models/repo_language_stats.go
+++ b/models/repo_language_stats.go
@@ -8,6 +8,7 @@ import (
 	"math"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/timeutil"
 
 	"github.com/go-enry/go-enry/v2"
@@ -26,6 +27,10 @@ type LanguageStat struct {
 	CreatedUnix timeutil.TimeStamp `xorm:"INDEX CREATED"`
 }
 
+func init() {
+	db.RegisterModel(new(LanguageStat))
+}
+
 // LanguageStatList defines a list of language statistics
 type LanguageStatList []*LanguageStat
 
@@ -60,7 +65,7 @@ func (stats LanguageStatList) getLanguagePercentages() map[string]float32 {
 	return langPerc
 }
 
-func (repo *Repository) getLanguageStats(e Engine) (LanguageStatList, error) {
+func (repo *Repository) getLanguageStats(e db.Engine) (LanguageStatList, error) {
 	stats := make(LanguageStatList, 0, 6)
 	if err := e.Where("`repo_id` = ?", repo.ID).Desc("`size`").Find(&stats); err != nil {
 		return nil, err
@@ -70,12 +75,12 @@ func (repo *Repository) getLanguageStats(e Engine) (LanguageStatList, error) {
 
 // GetLanguageStats returns the language statistics for a repository
 func (repo *Repository) GetLanguageStats() (LanguageStatList, error) {
-	return repo.getLanguageStats(x)
+	return repo.getLanguageStats(db.DefaultContext().Engine())
 }
 
 // GetTopLanguageStats returns the top language statistics for a repository
 func (repo *Repository) GetTopLanguageStats(limit int) (LanguageStatList, error) {
-	stats, err := repo.getLanguageStats(x)
+	stats, err := repo.getLanguageStats(db.DefaultContext().Engine())
 	if err != nil {
 		return nil, err
 	}
@@ -107,7 +112,7 @@ func (repo *Repository) GetTopLanguageStats(limit int) (LanguageStatList, error)
 
 // UpdateLanguageStats updates the language statistics for repository
 func (repo *Repository) UpdateLanguageStats(commitID string, stats map[string]int64) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	if err := sess.Begin(); err != nil {
 		return err
 	}
@@ -178,7 +183,7 @@ func (repo *Repository) UpdateLanguageStats(commitID string, stats map[string]in
 
 // CopyLanguageStat Copy originalRepo language stat information to destRepo (use for forked repo)
 func CopyLanguageStat(originalRepo, destRepo *Repository) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
diff --git a/models/repo_list.go b/models/repo_list.go
index 772bd20be..686fd27b7 100644
--- a/models/repo_list.go
+++ b/models/repo_list.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/util"
 
@@ -42,7 +43,7 @@ func RepositoryListOfMap(repoMap map[int64]*Repository) RepositoryList {
 	return RepositoryList(valuesRepository(repoMap))
 }
 
-func (repos RepositoryList) loadAttributes(e Engine) error {
+func (repos RepositoryList) loadAttributes(e db.Engine) error {
 	if len(repos) == 0 {
 		return nil
 	}
@@ -89,13 +90,13 @@ func (repos RepositoryList) loadAttributes(e Engine) error {
 
 // LoadAttributes loads the attributes for the given RepositoryList
 func (repos RepositoryList) LoadAttributes() error {
-	return repos.loadAttributes(x)
+	return repos.loadAttributes(db.DefaultContext().Engine())
 }
 
 // MirrorRepositoryList contains the mirror repositories
 type MirrorRepositoryList []*Repository
 
-func (repos MirrorRepositoryList) loadAttributes(e Engine) error {
+func (repos MirrorRepositoryList) loadAttributes(e db.Engine) error {
 	if len(repos) == 0 {
 		return nil
 	}
@@ -129,7 +130,7 @@ func (repos MirrorRepositoryList) loadAttributes(e Engine) error {
 
 // LoadAttributes loads the attributes for the given MirrorRepositoryList
 func (repos MirrorRepositoryList) LoadAttributes() error {
-	return repos.loadAttributes(x)
+	return repos.loadAttributes(db.DefaultContext().Engine())
 }
 
 // SearchRepoOptions holds the search options
@@ -409,7 +410,7 @@ func searchRepositoryByCondition(opts *SearchRepoOptions, cond builder.Cond) (*x
 		opts.OrderBy = SearchOrderBy(fmt.Sprintf("CASE WHEN owner_id = %d THEN 0 ELSE owner_id END, %s", opts.PriorityOwnerID, opts.OrderBy))
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 
 	var count int64
 	if opts.PageSize > 0 {
@@ -519,7 +520,7 @@ func AccessibleRepoIDsQuery(user *User) *builder.Builder {
 // FindUserAccessibleRepoIDs find all accessible repositories' ID by user's id
 func FindUserAccessibleRepoIDs(user *User) ([]int64, error) {
 	repoIDs := make([]int64, 0, 10)
-	if err := x.
+	if err := db.DefaultContext().Engine().
 		Table("repository").
 		Cols("id").
 		Where(accessibleRepositoryCondition(user)).
diff --git a/models/repo_list_test.go b/models/repo_list_test.go
index d1fefc3e3..a1fd454c1 100644
--- a/models/repo_list_test.go
+++ b/models/repo_list_test.go
@@ -7,13 +7,14 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/util"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestSearchRepository(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// test search public repository on explore page
 	repos, count, err := SearchRepositoryByName(&SearchRepoOptions{
@@ -76,7 +77,7 @@ func TestSearchRepository(t *testing.T) {
 	assert.Len(t, repos, 3)
 
 	// Test non existing owner
-	repos, count, err = SearchRepositoryByName(&SearchRepoOptions{OwnerID: NonexistentID})
+	repos, count, err = SearchRepositoryByName(&SearchRepoOptions{OwnerID: db.NonexistentID})
 
 	assert.NoError(t, err)
 	assert.Empty(t, repos)
@@ -323,7 +324,7 @@ func TestSearchRepository(t *testing.T) {
 }
 
 func TestSearchRepositoryByTopicName(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	testCases := []struct {
 		name  string
diff --git a/models/repo_mirror.go b/models/repo_mirror.go
index cd1f74cb2..b086b87cf 100644
--- a/models/repo_mirror.go
+++ b/models/repo_mirror.go
@@ -8,6 +8,7 @@ package models
 import (
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/timeutil"
 
@@ -37,6 +38,10 @@ type Mirror struct {
 	Address string `xorm:"-"`
 }
 
+func init() {
+	db.RegisterModel(new(Mirror))
+}
+
 // BeforeInsert will be invoked by XORM before inserting a record
 func (m *Mirror) BeforeInsert() {
 	if m != nil {
@@ -77,7 +82,7 @@ func (m *Mirror) ScheduleNextUpdate() {
 	}
 }
 
-func getMirrorByRepoID(e Engine, repoID int64) (*Mirror, error) {
+func getMirrorByRepoID(e db.Engine, repoID int64) (*Mirror, error) {
 	m := &Mirror{RepoID: repoID}
 	has, err := e.Get(m)
 	if err != nil {
@@ -90,28 +95,28 @@ func getMirrorByRepoID(e Engine, repoID int64) (*Mirror, error) {
 
 // GetMirrorByRepoID returns mirror information of a repository.
 func GetMirrorByRepoID(repoID int64) (*Mirror, error) {
-	return getMirrorByRepoID(x, repoID)
+	return getMirrorByRepoID(db.DefaultContext().Engine(), repoID)
 }
 
-func updateMirror(e Engine, m *Mirror) error {
+func updateMirror(e db.Engine, m *Mirror) error {
 	_, err := e.ID(m.ID).AllCols().Update(m)
 	return err
 }
 
 // UpdateMirror updates the mirror
 func UpdateMirror(m *Mirror) error {
-	return updateMirror(x, m)
+	return updateMirror(db.DefaultContext().Engine(), m)
 }
 
 // DeleteMirrorByRepoID deletes a mirror by repoID
 func DeleteMirrorByRepoID(repoID int64) error {
-	_, err := x.Delete(&Mirror{RepoID: repoID})
+	_, err := db.DefaultContext().Engine().Delete(&Mirror{RepoID: repoID})
 	return err
 }
 
 // MirrorsIterate iterates all mirror repositories.
 func MirrorsIterate(f func(idx int, bean interface{}) error) error {
-	return x.
+	return db.DefaultContext().Engine().
 		Where("next_update_unix<=?", time.Now().Unix()).
 		And("next_update_unix!=0").
 		Iterate(new(Mirror), f)
@@ -119,6 +124,6 @@ func MirrorsIterate(f func(idx int, bean interface{}) error) error {
 
 // InsertMirror inserts a mirror to database
 func InsertMirror(mirror *Mirror) error {
-	_, err := x.Insert(mirror)
+	_, err := db.DefaultContext().Engine().Insert(mirror)
 	return err
 }
diff --git a/models/repo_permission.go b/models/repo_permission.go
index f5138fc54..4f518e174 100644
--- a/models/repo_permission.go
+++ b/models/repo_permission.go
@@ -7,6 +7,7 @@ package models
 import (
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 )
 
@@ -139,10 +140,10 @@ func (p *Permission) ColorFormat(s fmt.State) {
 
 // GetUserRepoPermission returns the user permissions to the repository
 func GetUserRepoPermission(repo *Repository, user *User) (Permission, error) {
-	return getUserRepoPermission(x, repo, user)
+	return getUserRepoPermission(db.DefaultContext().Engine(), repo, user)
 }
 
-func getUserRepoPermission(e Engine, repo *Repository, user *User) (perm Permission, err error) {
+func getUserRepoPermission(e db.Engine, repo *Repository, user *User) (perm Permission, err error) {
 	if log.IsTrace() {
 		defer func() {
 			if user == nil {
@@ -277,7 +278,7 @@ func IsUserRealRepoAdmin(repo *Repository, user *User) (bool, error) {
 		return true, nil
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	if err := repo.getOwner(sess); err != nil {
@@ -294,10 +295,10 @@ func IsUserRealRepoAdmin(repo *Repository, user *User) (bool, error) {
 
 // IsUserRepoAdmin return true if user has admin right of a repo
 func IsUserRepoAdmin(repo *Repository, user *User) (bool, error) {
-	return isUserRepoAdmin(x, repo, user)
+	return isUserRepoAdmin(db.DefaultContext().Engine(), repo, user)
 }
 
-func isUserRepoAdmin(e Engine, repo *Repository, user *User) (bool, error) {
+func isUserRepoAdmin(e db.Engine, repo *Repository, user *User) (bool, error) {
 	if user == nil || repo == nil {
 		return false, nil
 	}
@@ -329,16 +330,16 @@ func isUserRepoAdmin(e Engine, repo *Repository, user *User) (bool, error) {
 // AccessLevel returns the Access a user has to a repository. Will return NoneAccess if the
 // user does not have access.
 func AccessLevel(user *User, repo *Repository) (AccessMode, error) {
-	return accessLevelUnit(x, user, repo, UnitTypeCode)
+	return accessLevelUnit(db.DefaultContext().Engine(), user, repo, UnitTypeCode)
 }
 
 // AccessLevelUnit returns the Access a user has to a repository's. Will return NoneAccess if the
 // user does not have access.
 func AccessLevelUnit(user *User, repo *Repository, unitType UnitType) (AccessMode, error) {
-	return accessLevelUnit(x, user, repo, unitType)
+	return accessLevelUnit(db.DefaultContext().Engine(), user, repo, unitType)
 }
 
-func accessLevelUnit(e Engine, user *User, repo *Repository, unitType UnitType) (AccessMode, error) {
+func accessLevelUnit(e db.Engine, user *User, repo *Repository, unitType UnitType) (AccessMode, error) {
 	perm, err := getUserRepoPermission(e, repo, user)
 	if err != nil {
 		return AccessModeNone, err
@@ -346,24 +347,24 @@ func accessLevelUnit(e Engine, user *User, repo *Repository, unitType UnitType)
 	return perm.UnitAccessMode(unitType), nil
 }
 
-func hasAccessUnit(e Engine, user *User, repo *Repository, unitType UnitType, testMode AccessMode) (bool, error) {
+func hasAccessUnit(e db.Engine, user *User, repo *Repository, unitType UnitType, testMode AccessMode) (bool, error) {
 	mode, err := accessLevelUnit(e, user, repo, unitType)
 	return testMode <= mode, err
 }
 
 // HasAccessUnit returns true if user has testMode to the unit of the repository
 func HasAccessUnit(user *User, repo *Repository, unitType UnitType, testMode AccessMode) (bool, error) {
-	return hasAccessUnit(x, user, repo, unitType, testMode)
+	return hasAccessUnit(db.DefaultContext().Engine(), user, repo, unitType, testMode)
 }
 
 // CanBeAssigned return true if user can be assigned to issue or pull requests in repo
 // Currently any write access (code, issues or pr's) is assignable, to match assignee list in user interface.
 // FIXME: user could send PullRequest also could be assigned???
 func CanBeAssigned(user *User, repo *Repository, isPull bool) (bool, error) {
-	return canBeAssigned(x, user, repo, isPull)
+	return canBeAssigned(db.DefaultContext().Engine(), user, repo, isPull)
 }
 
-func canBeAssigned(e Engine, user *User, repo *Repository, _ bool) (bool, error) {
+func canBeAssigned(e db.Engine, user *User, repo *Repository, _ bool) (bool, error) {
 	if user.IsOrganization() {
 		return false, fmt.Errorf("Organization can't be added as assignee [user_id: %d, repo_id: %d]", user.ID, repo.ID)
 	}
@@ -374,7 +375,7 @@ func canBeAssigned(e Engine, user *User, repo *Repository, _ bool) (bool, error)
 	return perm.CanAccessAny(AccessModeWrite, UnitTypeCode, UnitTypeIssues, UnitTypePullRequests), nil
 }
 
-func hasAccess(e Engine, userID int64, repo *Repository) (bool, error) {
+func hasAccess(e db.Engine, userID int64, repo *Repository) (bool, error) {
 	var user *User
 	var err error
 	if userID > 0 {
@@ -392,7 +393,7 @@ func hasAccess(e Engine, userID int64, repo *Repository) (bool, error) {
 
 // HasAccess returns true if user has access to repo
 func HasAccess(userID int64, repo *Repository) (bool, error) {
-	return hasAccess(x, userID, repo)
+	return hasAccess(db.DefaultContext().Engine(), userID, repo)
 }
 
 // FilterOutRepoIdsWithoutUnitAccess filter out repos where user has no access to repositories
diff --git a/models/repo_permission_test.go b/models/repo_permission_test.go
index 0f350e62a..625e0dd20 100644
--- a/models/repo_permission_test.go
+++ b/models/repo_permission_test.go
@@ -7,18 +7,19 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestRepoPermissionPublicNonOrgRepo(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// public non-organization repo
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 4}).(*Repository)
-	assert.NoError(t, repo.getUnits(x))
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 4}).(*Repository)
+	assert.NoError(t, repo.getUnits(db.DefaultContext().Engine()))
 
 	// plain user
-	user := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	perm, err := GetUserRepoPermission(repo, user)
 	assert.NoError(t, err)
 	for _, unit := range repo.Units {
@@ -36,7 +37,7 @@ func TestRepoPermissionPublicNonOrgRepo(t *testing.T) {
 	}
 
 	// collaborator
-	collaborator := AssertExistsAndLoadBean(t, &User{ID: 4}).(*User)
+	collaborator := db.AssertExistsAndLoadBean(t, &User{ID: 4}).(*User)
 	perm, err = GetUserRepoPermission(repo, collaborator)
 	assert.NoError(t, err)
 	for _, unit := range repo.Units {
@@ -45,7 +46,7 @@ func TestRepoPermissionPublicNonOrgRepo(t *testing.T) {
 	}
 
 	// owner
-	owner := AssertExistsAndLoadBean(t, &User{ID: 5}).(*User)
+	owner := db.AssertExistsAndLoadBean(t, &User{ID: 5}).(*User)
 	perm, err = GetUserRepoPermission(repo, owner)
 	assert.NoError(t, err)
 	for _, unit := range repo.Units {
@@ -54,7 +55,7 @@ func TestRepoPermissionPublicNonOrgRepo(t *testing.T) {
 	}
 
 	// admin
-	admin := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	admin := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 	perm, err = GetUserRepoPermission(repo, admin)
 	assert.NoError(t, err)
 	for _, unit := range repo.Units {
@@ -64,14 +65,14 @@ func TestRepoPermissionPublicNonOrgRepo(t *testing.T) {
 }
 
 func TestRepoPermissionPrivateNonOrgRepo(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// private non-organization repo
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 2}).(*Repository)
-	assert.NoError(t, repo.getUnits(x))
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 2}).(*Repository)
+	assert.NoError(t, repo.getUnits(db.DefaultContext().Engine()))
 
 	// plain user
-	user := AssertExistsAndLoadBean(t, &User{ID: 4}).(*User)
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 4}).(*User)
 	perm, err := GetUserRepoPermission(repo, user)
 	assert.NoError(t, err)
 	for _, unit := range repo.Units {
@@ -97,7 +98,7 @@ func TestRepoPermissionPrivateNonOrgRepo(t *testing.T) {
 	}
 
 	// owner
-	owner := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	owner := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	perm, err = GetUserRepoPermission(repo, owner)
 	assert.NoError(t, err)
 	for _, unit := range repo.Units {
@@ -106,7 +107,7 @@ func TestRepoPermissionPrivateNonOrgRepo(t *testing.T) {
 	}
 
 	// admin
-	admin := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	admin := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 	perm, err = GetUserRepoPermission(repo, admin)
 	assert.NoError(t, err)
 	for _, unit := range repo.Units {
@@ -116,14 +117,14 @@ func TestRepoPermissionPrivateNonOrgRepo(t *testing.T) {
 }
 
 func TestRepoPermissionPublicOrgRepo(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// public organization repo
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 32}).(*Repository)
-	assert.NoError(t, repo.getUnits(x))
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 32}).(*Repository)
+	assert.NoError(t, repo.getUnits(db.DefaultContext().Engine()))
 
 	// plain user
-	user := AssertExistsAndLoadBean(t, &User{ID: 5}).(*User)
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 5}).(*User)
 	perm, err := GetUserRepoPermission(repo, user)
 	assert.NoError(t, err)
 	for _, unit := range repo.Units {
@@ -149,7 +150,7 @@ func TestRepoPermissionPublicOrgRepo(t *testing.T) {
 	}
 
 	// org member team owner
-	owner := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	owner := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	perm, err = GetUserRepoPermission(repo, owner)
 	assert.NoError(t, err)
 	for _, unit := range repo.Units {
@@ -158,7 +159,7 @@ func TestRepoPermissionPublicOrgRepo(t *testing.T) {
 	}
 
 	// org member team tester
-	member := AssertExistsAndLoadBean(t, &User{ID: 15}).(*User)
+	member := db.AssertExistsAndLoadBean(t, &User{ID: 15}).(*User)
 	perm, err = GetUserRepoPermission(repo, member)
 	assert.NoError(t, err)
 	for _, unit := range repo.Units {
@@ -168,7 +169,7 @@ func TestRepoPermissionPublicOrgRepo(t *testing.T) {
 	assert.False(t, perm.CanWrite(UnitTypeCode))
 
 	// admin
-	admin := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	admin := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 	perm, err = GetUserRepoPermission(repo, admin)
 	assert.NoError(t, err)
 	for _, unit := range repo.Units {
@@ -178,14 +179,14 @@ func TestRepoPermissionPublicOrgRepo(t *testing.T) {
 }
 
 func TestRepoPermissionPrivateOrgRepo(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// private organization repo
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 24}).(*Repository)
-	assert.NoError(t, repo.getUnits(x))
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 24}).(*Repository)
+	assert.NoError(t, repo.getUnits(db.DefaultContext().Engine()))
 
 	// plain user
-	user := AssertExistsAndLoadBean(t, &User{ID: 5}).(*User)
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 5}).(*User)
 	perm, err := GetUserRepoPermission(repo, user)
 	assert.NoError(t, err)
 	for _, unit := range repo.Units {
@@ -211,7 +212,7 @@ func TestRepoPermissionPrivateOrgRepo(t *testing.T) {
 	}
 
 	// org member team owner
-	owner := AssertExistsAndLoadBean(t, &User{ID: 15}).(*User)
+	owner := db.AssertExistsAndLoadBean(t, &User{ID: 15}).(*User)
 	perm, err = GetUserRepoPermission(repo, owner)
 	assert.NoError(t, err)
 	for _, unit := range repo.Units {
@@ -220,7 +221,7 @@ func TestRepoPermissionPrivateOrgRepo(t *testing.T) {
 	}
 
 	// update team information and then check permission
-	team := AssertExistsAndLoadBean(t, &Team{ID: 5}).(*Team)
+	team := db.AssertExistsAndLoadBean(t, &Team{ID: 5}).(*Team)
 	err = UpdateTeamUnits(team, nil)
 	assert.NoError(t, err)
 	perm, err = GetUserRepoPermission(repo, owner)
@@ -231,7 +232,7 @@ func TestRepoPermissionPrivateOrgRepo(t *testing.T) {
 	}
 
 	// org member team tester
-	tester := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	tester := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	perm, err = GetUserRepoPermission(repo, tester)
 	assert.NoError(t, err)
 	assert.True(t, perm.CanWrite(UnitTypeIssues))
@@ -239,7 +240,7 @@ func TestRepoPermissionPrivateOrgRepo(t *testing.T) {
 	assert.False(t, perm.CanRead(UnitTypeCode))
 
 	// org member team reviewer
-	reviewer := AssertExistsAndLoadBean(t, &User{ID: 20}).(*User)
+	reviewer := db.AssertExistsAndLoadBean(t, &User{ID: 20}).(*User)
 	perm, err = GetUserRepoPermission(repo, reviewer)
 	assert.NoError(t, err)
 	assert.False(t, perm.CanRead(UnitTypeIssues))
@@ -247,7 +248,7 @@ func TestRepoPermissionPrivateOrgRepo(t *testing.T) {
 	assert.True(t, perm.CanRead(UnitTypeCode))
 
 	// admin
-	admin := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	admin := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 	perm, err = GetUserRepoPermission(repo, admin)
 	assert.NoError(t, err)
 	for _, unit := range repo.Units {
diff --git a/models/repo_pushmirror.go b/models/repo_pushmirror.go
index 439972ffa..b0e285216 100644
--- a/models/repo_pushmirror.go
+++ b/models/repo_pushmirror.go
@@ -8,6 +8,7 @@ import (
 	"errors"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/timeutil"
 
@@ -32,6 +33,10 @@ type PushMirror struct {
 	LastError      string             `xorm:"text"`
 }
 
+func init() {
+	db.RegisterModel(new(PushMirror))
+}
+
 // AfterLoad is invoked from XORM after setting the values of all fields of this object.
 func (m *PushMirror) AfterLoad(session *xorm.Session) {
 	if m == nil {
@@ -57,32 +62,32 @@ func (m *PushMirror) GetRemoteName() string {
 
 // InsertPushMirror inserts a push-mirror to database
 func InsertPushMirror(m *PushMirror) error {
-	_, err := x.Insert(m)
+	_, err := db.DefaultContext().Engine().Insert(m)
 	return err
 }
 
 // UpdatePushMirror updates the push-mirror
 func UpdatePushMirror(m *PushMirror) error {
-	_, err := x.ID(m.ID).AllCols().Update(m)
+	_, err := db.DefaultContext().Engine().ID(m.ID).AllCols().Update(m)
 	return err
 }
 
 // DeletePushMirrorByID deletes a push-mirrors by ID
 func DeletePushMirrorByID(ID int64) error {
-	_, err := x.ID(ID).Delete(&PushMirror{})
+	_, err := db.DefaultContext().Engine().ID(ID).Delete(&PushMirror{})
 	return err
 }
 
 // DeletePushMirrorsByRepoID deletes all push-mirrors by repoID
 func DeletePushMirrorsByRepoID(repoID int64) error {
-	_, err := x.Delete(&PushMirror{RepoID: repoID})
+	_, err := db.DefaultContext().Engine().Delete(&PushMirror{RepoID: repoID})
 	return err
 }
 
 // GetPushMirrorByID returns push-mirror information.
 func GetPushMirrorByID(ID int64) (*PushMirror, error) {
 	m := &PushMirror{}
-	has, err := x.ID(ID).Get(m)
+	has, err := db.DefaultContext().Engine().ID(ID).Get(m)
 	if err != nil {
 		return nil, err
 	} else if !has {
@@ -94,12 +99,12 @@ func GetPushMirrorByID(ID int64) (*PushMirror, error) {
 // GetPushMirrorsByRepoID returns push-mirror information of a repository.
 func GetPushMirrorsByRepoID(repoID int64) ([]*PushMirror, error) {
 	mirrors := make([]*PushMirror, 0, 10)
-	return mirrors, x.Where("repo_id=?", repoID).Find(&mirrors)
+	return mirrors, db.DefaultContext().Engine().Where("repo_id=?", repoID).Find(&mirrors)
 }
 
 // PushMirrorsIterate iterates all push-mirror repositories.
 func PushMirrorsIterate(f func(idx int, bean interface{}) error) error {
-	return x.
+	return db.DefaultContext().Engine().
 		Where("last_update + (`interval` / ?) <= ?", time.Second, time.Now().Unix()).
 		And("`interval` != 0").
 		Iterate(new(PushMirror), f)
diff --git a/models/repo_pushmirror_test.go b/models/repo_pushmirror_test.go
index 66c499b1c..65ef91814 100644
--- a/models/repo_pushmirror_test.go
+++ b/models/repo_pushmirror_test.go
@@ -8,13 +8,14 @@ import (
 	"testing"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/timeutil"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestPushMirrorsIterate(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	now := timeutil.TimeStampNow()
 
diff --git a/models/repo_redirect.go b/models/repo_redirect.go
index afbfeb499..95196d2a0 100644
--- a/models/repo_redirect.go
+++ b/models/repo_redirect.go
@@ -6,6 +6,8 @@ package models
 
 import (
 	"strings"
+
+	"code.gitea.io/gitea/models/db"
 )
 
 // RepoRedirect represents that a repo name should be redirected to another
@@ -16,11 +18,15 @@ type RepoRedirect struct {
 	RedirectRepoID int64  // repoID to redirect to
 }
 
+func init() {
+	db.RegisterModel(new(RepoRedirect))
+}
+
 // LookupRepoRedirect look up if a repository has a redirect name
 func LookupRepoRedirect(ownerID int64, repoName string) (int64, error) {
 	repoName = strings.ToLower(repoName)
 	redirect := &RepoRedirect{OwnerID: ownerID, LowerName: repoName}
-	if has, err := x.Get(redirect); err != nil {
+	if has, err := db.DefaultContext().Engine().Get(redirect); err != nil {
 		return 0, err
 	} else if !has {
 		return 0, ErrRepoRedirectNotExist{OwnerID: ownerID, RepoName: repoName}
@@ -29,7 +35,7 @@ func LookupRepoRedirect(ownerID int64, repoName string) (int64, error) {
 }
 
 // newRepoRedirect create a new repo redirect
-func newRepoRedirect(e Engine, ownerID, repoID int64, oldRepoName, newRepoName string) error {
+func newRepoRedirect(e db.Engine, ownerID, repoID int64, oldRepoName, newRepoName string) error {
 	oldRepoName = strings.ToLower(oldRepoName)
 	newRepoName = strings.ToLower(newRepoName)
 
@@ -49,7 +55,7 @@ func newRepoRedirect(e Engine, ownerID, repoID int64, oldRepoName, newRepoName s
 
 // deleteRepoRedirect delete any redirect from the specified repo name to
 // anything else
-func deleteRepoRedirect(e Engine, ownerID int64, repoName string) error {
+func deleteRepoRedirect(e db.Engine, ownerID int64, repoName string) error {
 	repoName = strings.ToLower(repoName)
 	_, err := e.Delete(&RepoRedirect{OwnerID: ownerID, LowerName: repoName})
 	return err
diff --git a/models/repo_redirect_test.go b/models/repo_redirect_test.go
index 4c3184a0f..9e99fdae3 100644
--- a/models/repo_redirect_test.go
+++ b/models/repo_redirect_test.go
@@ -7,33 +7,34 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestLookupRepoRedirect(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	repoID, err := LookupRepoRedirect(2, "oldrepo1")
 	assert.NoError(t, err)
 	assert.EqualValues(t, 1, repoID)
 
-	_, err = LookupRepoRedirect(NonexistentID, "doesnotexist")
+	_, err = LookupRepoRedirect(db.NonexistentID, "doesnotexist")
 	assert.True(t, IsErrRepoRedirectNotExist(err))
 }
 
 func TestNewRepoRedirect(t *testing.T) {
 	// redirect to a completely new name
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
-	assert.NoError(t, newRepoRedirect(x, repo.OwnerID, repo.ID, repo.Name, "newreponame"))
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	assert.NoError(t, newRepoRedirect(db.DefaultContext().Engine(), repo.OwnerID, repo.ID, repo.Name, "newreponame"))
 
-	AssertExistsAndLoadBean(t, &RepoRedirect{
+	db.AssertExistsAndLoadBean(t, &RepoRedirect{
 		OwnerID:        repo.OwnerID,
 		LowerName:      repo.LowerName,
 		RedirectRepoID: repo.ID,
 	})
-	AssertExistsAndLoadBean(t, &RepoRedirect{
+	db.AssertExistsAndLoadBean(t, &RepoRedirect{
 		OwnerID:        repo.OwnerID,
 		LowerName:      "oldrepo1",
 		RedirectRepoID: repo.ID,
@@ -42,17 +43,17 @@ func TestNewRepoRedirect(t *testing.T) {
 
 func TestNewRepoRedirect2(t *testing.T) {
 	// redirect to previously used name
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
-	assert.NoError(t, newRepoRedirect(x, repo.OwnerID, repo.ID, repo.Name, "oldrepo1"))
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	assert.NoError(t, newRepoRedirect(db.DefaultContext().Engine(), repo.OwnerID, repo.ID, repo.Name, "oldrepo1"))
 
-	AssertExistsAndLoadBean(t, &RepoRedirect{
+	db.AssertExistsAndLoadBean(t, &RepoRedirect{
 		OwnerID:        repo.OwnerID,
 		LowerName:      repo.LowerName,
 		RedirectRepoID: repo.ID,
 	})
-	AssertNotExistsBean(t, &RepoRedirect{
+	db.AssertNotExistsBean(t, &RepoRedirect{
 		OwnerID:        repo.OwnerID,
 		LowerName:      "oldrepo1",
 		RedirectRepoID: repo.ID,
@@ -61,12 +62,12 @@ func TestNewRepoRedirect2(t *testing.T) {
 
 func TestNewRepoRedirect3(t *testing.T) {
 	// redirect for a previously-unredirected repo
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 2}).(*Repository)
-	assert.NoError(t, newRepoRedirect(x, repo.OwnerID, repo.ID, repo.Name, "newreponame"))
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 2}).(*Repository)
+	assert.NoError(t, newRepoRedirect(db.DefaultContext().Engine(), repo.OwnerID, repo.ID, repo.Name, "newreponame"))
 
-	AssertExistsAndLoadBean(t, &RepoRedirect{
+	db.AssertExistsAndLoadBean(t, &RepoRedirect{
 		OwnerID:        repo.OwnerID,
 		LowerName:      repo.LowerName,
 		RedirectRepoID: repo.ID,
diff --git a/models/repo_test.go b/models/repo_test.go
index 28eb9baa1..2467b6384 100644
--- a/models/repo_test.go
+++ b/models/repo_test.go
@@ -12,13 +12,14 @@ import (
 	"image/png"
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/markup"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestMetas(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	repo := &Repository{Name: "testRepo"}
 	repo.Owner = &User{Name: "testOwner"}
@@ -66,7 +67,7 @@ func TestMetas(t *testing.T) {
 }
 
 func TestGetRepositoryCount(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	count, err1 := GetRepositoryCount(&User{ID: int64(10)})
 	privateCount, err2 := GetPrivateRepositoryCount(&User{ID: int64(10)})
@@ -79,7 +80,7 @@ func TestGetRepositoryCount(t *testing.T) {
 }
 
 func TestGetPublicRepositoryCount(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	count, err := GetPublicRepositoryCount(&User{ID: int64(10)})
 	assert.NoError(t, err)
@@ -87,7 +88,7 @@ func TestGetPublicRepositoryCount(t *testing.T) {
 }
 
 func TestGetPrivateRepositoryCount(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	count, err := GetPrivateRepositoryCount(&User{ID: int64(10)})
 	assert.NoError(t, err)
@@ -95,7 +96,7 @@ func TestGetPrivateRepositoryCount(t *testing.T) {
 }
 
 func TestUpdateRepositoryVisibilityChanged(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// Get sample repo and change visibility
 	repo, err := GetRepositoryByID(9)
@@ -108,14 +109,14 @@ func TestUpdateRepositoryVisibilityChanged(t *testing.T) {
 
 	// Check visibility of action has become private
 	act := Action{}
-	_, err = x.ID(3).Get(&act)
+	_, err = db.DefaultContext().Engine().ID(3).Get(&act)
 
 	assert.NoError(t, err)
 	assert.True(t, act.IsPrivate)
 }
 
 func TestGetUserFork(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// User13 has repo 11 forked from repo10
 	repo, err := GetRepositoryByID(10)
@@ -134,8 +135,8 @@ func TestGetUserFork(t *testing.T) {
 }
 
 func TestRepoAPIURL(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 10}).(*Repository)
+	assert.NoError(t, db.PrepareTestDatabase())
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 10}).(*Repository)
 
 	assert.Equal(t, "https://try.gitea.io/api/v1/repos/user12/repo10", repo.APIURL())
 }
@@ -146,8 +147,8 @@ func TestUploadAvatar(t *testing.T) {
 	var buff bytes.Buffer
 	png.Encode(&buff, myImage)
 
-	assert.NoError(t, PrepareTestDatabase())
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 10}).(*Repository)
+	assert.NoError(t, db.PrepareTestDatabase())
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 10}).(*Repository)
 
 	err := repo.UploadAvatar(buff.Bytes())
 	assert.NoError(t, err)
@@ -160,8 +161,8 @@ func TestUploadBigAvatar(t *testing.T) {
 	var buff bytes.Buffer
 	png.Encode(&buff, myImage)
 
-	assert.NoError(t, PrepareTestDatabase())
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 10}).(*Repository)
+	assert.NoError(t, db.PrepareTestDatabase())
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 10}).(*Repository)
 
 	err := repo.UploadAvatar(buff.Bytes())
 	assert.Error(t, err)
@@ -173,8 +174,8 @@ func TestDeleteAvatar(t *testing.T) {
 	var buff bytes.Buffer
 	png.Encode(&buff, myImage)
 
-	assert.NoError(t, PrepareTestDatabase())
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 10}).(*Repository)
+	assert.NoError(t, db.PrepareTestDatabase())
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 10}).(*Repository)
 
 	err := repo.UploadAvatar(buff.Bytes())
 	assert.NoError(t, err)
@@ -186,37 +187,37 @@ func TestDeleteAvatar(t *testing.T) {
 }
 
 func TestDoctorUserStarNum(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	assert.NoError(t, DoctorUserStarNum())
 }
 
 func TestRepoGetReviewers(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// test public repo
-	repo1 := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	repo1 := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
 
 	reviewers, err := repo1.GetReviewers(2, 2)
 	assert.NoError(t, err)
 	assert.Len(t, reviewers, 4)
 
 	// test private repo
-	repo2 := AssertExistsAndLoadBean(t, &Repository{ID: 2}).(*Repository)
+	repo2 := db.AssertExistsAndLoadBean(t, &Repository{ID: 2}).(*Repository)
 	reviewers, err = repo2.GetReviewers(2, 2)
 	assert.NoError(t, err)
 	assert.Empty(t, reviewers)
 }
 
 func TestRepoGetReviewerTeams(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	repo2 := AssertExistsAndLoadBean(t, &Repository{ID: 2}).(*Repository)
+	repo2 := db.AssertExistsAndLoadBean(t, &Repository{ID: 2}).(*Repository)
 	teams, err := repo2.GetReviewerTeams()
 	assert.NoError(t, err)
 	assert.Empty(t, teams)
 
-	repo3 := AssertExistsAndLoadBean(t, &Repository{ID: 3}).(*Repository)
+	repo3 := db.AssertExistsAndLoadBean(t, &Repository{ID: 3}).(*Repository)
 	teams, err = repo3.GetReviewerTeams()
 	assert.NoError(t, err)
 	assert.Len(t, teams, 2)
diff --git a/models/repo_transfer.go b/models/repo_transfer.go
index 09b629029..2ede0fbbe 100644
--- a/models/repo_transfer.go
+++ b/models/repo_transfer.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"os"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/util"
@@ -28,6 +29,10 @@ type RepoTransfer struct {
 	UpdatedUnix timeutil.TimeStamp `xorm:"INDEX NOT NULL updated"`
 }
 
+func init() {
+	db.RegisterModel(new(RepoTransfer))
+}
+
 // LoadAttributes fetches the transfer recipient from the database
 func (r *RepoTransfer) LoadAttributes() error {
 	if r.Recipient == nil {
@@ -93,7 +98,7 @@ func (r *RepoTransfer) CanUserAcceptTransfer(u *User) bool {
 func GetPendingRepositoryTransfer(repo *Repository) (*RepoTransfer, error) {
 	transfer := new(RepoTransfer)
 
-	has, err := x.Where("repo_id = ? ", repo.ID).Get(transfer)
+	has, err := db.DefaultContext().Engine().Where("repo_id = ? ", repo.ID).Get(transfer)
 	if err != nil {
 		return nil, err
 	}
@@ -105,7 +110,7 @@ func GetPendingRepositoryTransfer(repo *Repository) (*RepoTransfer, error) {
 	return transfer, nil
 }
 
-func deleteRepositoryTransfer(e Engine, repoID int64) error {
+func deleteRepositoryTransfer(e db.Engine, repoID int64) error {
 	_, err := e.Where("repo_id = ?", repoID).Delete(&RepoTransfer{})
 	return err
 }
@@ -113,7 +118,7 @@ func deleteRepositoryTransfer(e Engine, repoID int64) error {
 // CancelRepositoryTransfer marks the repository as ready and remove pending transfer entry,
 // thus cancel the transfer process.
 func CancelRepositoryTransfer(repo *Repository) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -145,7 +150,7 @@ func TestRepositoryReadyForTransfer(status RepositoryStatus) error {
 // CreatePendingRepositoryTransfer transfer a repo from one owner to a new one.
 // it marks the repository transfer as "pending"
 func CreatePendingRepositoryTransfer(doer, newOwner *User, repoID int64, teams []*Team) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -227,7 +232,7 @@ func TransferOwnership(doer *User, newOwnerName string, repo *Repository) (err e
 		}
 	}()
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return fmt.Errorf("sess.Begin: %v", err)
diff --git a/models/repo_transfer_test.go b/models/repo_transfer_test.go
index 8b1aba896..4c6b7254c 100644
--- a/models/repo_transfer_test.go
+++ b/models/repo_transfer_test.go
@@ -7,14 +7,15 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestRepositoryTransfer(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	doer := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 3}).(*Repository)
+	doer := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 3}).(*Repository)
 
 	transfer, err := GetPendingRepositoryTransfer(repo)
 	assert.NoError(t, err)
@@ -28,7 +29,7 @@ func TestRepositoryTransfer(t *testing.T) {
 	assert.Nil(t, transfer)
 	assert.True(t, IsErrNoPendingTransfer(err))
 
-	user2 := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user2 := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 
 	assert.NoError(t, CreatePendingRepositoryTransfer(doer, user2, repo.ID, nil))
 
@@ -37,7 +38,7 @@ func TestRepositoryTransfer(t *testing.T) {
 	assert.NoError(t, transfer.LoadAttributes())
 	assert.Equal(t, "user2", transfer.Recipient.Name)
 
-	user6 := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user6 := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 
 	// Only transfer can be started at any given time
 	err = CreatePendingRepositoryTransfer(doer, user6, repo.ID, nil)
diff --git a/models/repo_unit.go b/models/repo_unit.go
index 2a20205fe..c35312be6 100644
--- a/models/repo_unit.go
+++ b/models/repo_unit.go
@@ -7,6 +7,7 @@ package models
 import (
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/json"
 	"code.gitea.io/gitea/modules/timeutil"
 
@@ -23,6 +24,10 @@ type RepoUnit struct {
 	CreatedUnix timeutil.TimeStamp `xorm:"INDEX CREATED"`
 }
 
+func init() {
+	db.RegisterModel(new(RepoUnit))
+}
+
 // UnitConfig describes common unit config
 type UnitConfig struct{}
 
@@ -200,7 +205,7 @@ func (r *RepoUnit) ExternalTrackerConfig() *ExternalTrackerConfig {
 	return r.Config.(*ExternalTrackerConfig)
 }
 
-func getUnitsByRepoID(e Engine, repoID int64) (units []*RepoUnit, err error) {
+func getUnitsByRepoID(e db.Engine, repoID int64) (units []*RepoUnit, err error) {
 	var tmpUnits []*RepoUnit
 	if err := e.Where("repo_id = ?", repoID).Find(&tmpUnits); err != nil {
 		return nil, err
diff --git a/models/repo_watch.go b/models/repo_watch.go
index 043449f0e..635507561 100644
--- a/models/repo_watch.go
+++ b/models/repo_watch.go
@@ -7,6 +7,7 @@ package models
 import (
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/timeutil"
 )
@@ -35,8 +36,12 @@ type Watch struct {
 	UpdatedUnix timeutil.TimeStamp `xorm:"INDEX updated"`
 }
 
+func init() {
+	db.RegisterModel(new(Watch))
+}
+
 // getWatch gets what kind of subscription a user has on a given repository; returns dummy record if none found
-func getWatch(e Engine, userID, repoID int64) (Watch, error) {
+func getWatch(e db.Engine, userID, repoID int64) (Watch, error) {
 	watch := Watch{UserID: userID, RepoID: repoID}
 	has, err := e.Get(&watch)
 	if err != nil {
@@ -55,11 +60,11 @@ func isWatchMode(mode RepoWatchMode) bool {
 
 // IsWatching checks if user has watched given repository.
 func IsWatching(userID, repoID int64) bool {
-	watch, err := getWatch(x, userID, repoID)
+	watch, err := getWatch(db.DefaultContext().Engine(), userID, repoID)
 	return err == nil && isWatchMode(watch.Mode)
 }
 
-func watchRepoMode(e Engine, watch Watch, mode RepoWatchMode) (err error) {
+func watchRepoMode(e db.Engine, watch Watch, mode RepoWatchMode) (err error) {
 	if watch.Mode == mode {
 		return nil
 	}
@@ -102,13 +107,13 @@ func watchRepoMode(e Engine, watch Watch, mode RepoWatchMode) (err error) {
 // WatchRepoMode watch repository in specific mode.
 func WatchRepoMode(userID, repoID int64, mode RepoWatchMode) (err error) {
 	var watch Watch
-	if watch, err = getWatch(x, userID, repoID); err != nil {
+	if watch, err = getWatch(db.DefaultContext().Engine(), userID, repoID); err != nil {
 		return err
 	}
-	return watchRepoMode(x, watch, mode)
+	return watchRepoMode(db.DefaultContext().Engine(), watch, mode)
 }
 
-func watchRepo(e Engine, userID, repoID int64, doWatch bool) (err error) {
+func watchRepo(e db.Engine, userID, repoID int64, doWatch bool) (err error) {
 	var watch Watch
 	if watch, err = getWatch(e, userID, repoID); err != nil {
 		return err
@@ -125,10 +130,10 @@ func watchRepo(e Engine, userID, repoID int64, doWatch bool) (err error) {
 
 // WatchRepo watch or unwatch repository.
 func WatchRepo(userID, repoID int64, watch bool) (err error) {
-	return watchRepo(x, userID, repoID, watch)
+	return watchRepo(db.DefaultContext().Engine(), userID, repoID, watch)
 }
 
-func getWatchers(e Engine, repoID int64) ([]*Watch, error) {
+func getWatchers(e db.Engine, repoID int64) ([]*Watch, error) {
 	watches := make([]*Watch, 0, 10)
 	return watches, e.Where("`watch`.repo_id=?", repoID).
 		And("`watch`.mode<>?", RepoWatchModeDont).
@@ -140,17 +145,17 @@ func getWatchers(e Engine, repoID int64) ([]*Watch, error) {
 
 // GetWatchers returns all watchers of given repository.
 func GetWatchers(repoID int64) ([]*Watch, error) {
-	return getWatchers(x, repoID)
+	return getWatchers(db.DefaultContext().Engine(), repoID)
 }
 
 // GetRepoWatchersIDs returns IDs of watchers for a given repo ID
 // but avoids joining with `user` for performance reasons
 // User permissions must be verified elsewhere if required
 func GetRepoWatchersIDs(repoID int64) ([]int64, error) {
-	return getRepoWatchersIDs(x, repoID)
+	return getRepoWatchersIDs(db.DefaultContext().Engine(), repoID)
 }
 
-func getRepoWatchersIDs(e Engine, repoID int64) ([]int64, error) {
+func getRepoWatchersIDs(e db.Engine, repoID int64) ([]int64, error) {
 	ids := make([]int64, 0, 64)
 	return ids, e.Table("watch").
 		Where("watch.repo_id=?", repoID).
@@ -161,7 +166,7 @@ func getRepoWatchersIDs(e Engine, repoID int64) ([]int64, error) {
 
 // GetWatchers returns range of users watching given repository.
 func (repo *Repository) GetWatchers(opts ListOptions) ([]*User, error) {
-	sess := x.Where("watch.repo_id=?", repo.ID).
+	sess := db.DefaultContext().Engine().Where("watch.repo_id=?", repo.ID).
 		Join("LEFT", "watch", "`user`.id=`watch`.user_id").
 		And("`watch`.mode<>?", RepoWatchModeDont)
 	if opts.Page > 0 {
@@ -175,7 +180,7 @@ func (repo *Repository) GetWatchers(opts ListOptions) ([]*User, error) {
 	return users, sess.Find(&users)
 }
 
-func notifyWatchers(e Engine, actions ...*Action) error {
+func notifyWatchers(e db.Engine, actions ...*Action) error {
 	var watchers []*Watch
 	var repo *Repository
 	var err error
@@ -279,12 +284,12 @@ func notifyWatchers(e Engine, actions ...*Action) error {
 
 // NotifyWatchers creates batch of actions for every watcher.
 func NotifyWatchers(actions ...*Action) error {
-	return notifyWatchers(x, actions...)
+	return notifyWatchers(db.DefaultContext().Engine(), actions...)
 }
 
 // NotifyWatchersActions creates batch of actions for every watcher.
 func NotifyWatchersActions(acts []*Action) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -297,7 +302,7 @@ func NotifyWatchersActions(acts []*Action) error {
 	return sess.Commit()
 }
 
-func watchIfAuto(e Engine, userID, repoID int64, isWrite bool) error {
+func watchIfAuto(e db.Engine, userID, repoID int64, isWrite bool) error {
 	if !isWrite || !setting.Service.AutoWatchOnChanges {
 		return nil
 	}
@@ -313,5 +318,5 @@ func watchIfAuto(e Engine, userID, repoID int64, isWrite bool) error {
 
 // WatchIfAuto subscribes to repo if AutoWatchOnChanges is set
 func WatchIfAuto(userID, repoID int64, isWrite bool) error {
-	return watchIfAuto(x, userID, repoID, isWrite)
+	return watchIfAuto(db.DefaultContext().Engine(), userID, repoID, isWrite)
 }
diff --git a/models/repo_watch_test.go b/models/repo_watch_test.go
index e1bbc4023..1a94b8ad3 100644
--- a/models/repo_watch_test.go
+++ b/models/repo_watch_test.go
@@ -7,13 +7,14 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestIsWatching(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	assert.True(t, IsWatching(1, 1))
 	assert.True(t, IsWatching(4, 1))
@@ -21,27 +22,27 @@ func TestIsWatching(t *testing.T) {
 
 	assert.False(t, IsWatching(1, 5))
 	assert.False(t, IsWatching(8, 1))
-	assert.False(t, IsWatching(NonexistentID, NonexistentID))
+	assert.False(t, IsWatching(db.NonexistentID, db.NonexistentID))
 }
 
 func TestWatchRepo(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	const repoID = 3
 	const userID = 2
 
 	assert.NoError(t, WatchRepo(userID, repoID, true))
-	AssertExistsAndLoadBean(t, &Watch{RepoID: repoID, UserID: userID})
+	db.AssertExistsAndLoadBean(t, &Watch{RepoID: repoID, UserID: userID})
 	CheckConsistencyFor(t, &Repository{ID: repoID})
 
 	assert.NoError(t, WatchRepo(userID, repoID, false))
-	AssertNotExistsBean(t, &Watch{RepoID: repoID, UserID: userID})
+	db.AssertNotExistsBean(t, &Watch{RepoID: repoID, UserID: userID})
 	CheckConsistencyFor(t, &Repository{ID: repoID})
 }
 
 func TestGetWatchers(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
 	watches, err := GetWatchers(repo.ID)
 	assert.NoError(t, err)
 	// One watchers are inactive, thus minus 1
@@ -50,30 +51,30 @@ func TestGetWatchers(t *testing.T) {
 		assert.EqualValues(t, repo.ID, watch.RepoID)
 	}
 
-	watches, err = GetWatchers(NonexistentID)
+	watches, err = GetWatchers(db.NonexistentID)
 	assert.NoError(t, err)
 	assert.Len(t, watches, 0)
 }
 
 func TestRepository_GetWatchers(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
 	watchers, err := repo.GetWatchers(ListOptions{Page: 1})
 	assert.NoError(t, err)
 	assert.Len(t, watchers, repo.NumWatches)
 	for _, watcher := range watchers {
-		AssertExistsAndLoadBean(t, &Watch{UserID: watcher.ID, RepoID: repo.ID})
+		db.AssertExistsAndLoadBean(t, &Watch{UserID: watcher.ID, RepoID: repo.ID})
 	}
 
-	repo = AssertExistsAndLoadBean(t, &Repository{ID: 9}).(*Repository)
+	repo = db.AssertExistsAndLoadBean(t, &Repository{ID: 9}).(*Repository)
 	watchers, err = repo.GetWatchers(ListOptions{Page: 1})
 	assert.NoError(t, err)
 	assert.Len(t, watchers, 0)
 }
 
 func TestNotifyWatchers(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	action := &Action{
 		ActUserID: 8,
@@ -83,25 +84,25 @@ func TestNotifyWatchers(t *testing.T) {
 	assert.NoError(t, NotifyWatchers(action))
 
 	// One watchers are inactive, thus action is only created for user 8, 1, 4, 11
-	AssertExistsAndLoadBean(t, &Action{
+	db.AssertExistsAndLoadBean(t, &Action{
 		ActUserID: action.ActUserID,
 		UserID:    8,
 		RepoID:    action.RepoID,
 		OpType:    action.OpType,
 	})
-	AssertExistsAndLoadBean(t, &Action{
+	db.AssertExistsAndLoadBean(t, &Action{
 		ActUserID: action.ActUserID,
 		UserID:    1,
 		RepoID:    action.RepoID,
 		OpType:    action.OpType,
 	})
-	AssertExistsAndLoadBean(t, &Action{
+	db.AssertExistsAndLoadBean(t, &Action{
 		ActUserID: action.ActUserID,
 		UserID:    4,
 		RepoID:    action.RepoID,
 		OpType:    action.OpType,
 	})
-	AssertExistsAndLoadBean(t, &Action{
+	db.AssertExistsAndLoadBean(t, &Action{
 		ActUserID: action.ActUserID,
 		UserID:    11,
 		RepoID:    action.RepoID,
@@ -110,9 +111,9 @@ func TestNotifyWatchers(t *testing.T) {
 }
 
 func TestWatchIfAuto(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
 	watchers, err := repo.GetWatchers(ListOptions{Page: 1})
 	assert.NoError(t, err)
 	assert.Len(t, watchers, repo.NumWatches)
@@ -167,22 +168,22 @@ func TestWatchIfAuto(t *testing.T) {
 }
 
 func TestWatchRepoMode(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	AssertCount(t, &Watch{UserID: 12, RepoID: 1}, 0)
+	db.AssertCount(t, &Watch{UserID: 12, RepoID: 1}, 0)
 
 	assert.NoError(t, WatchRepoMode(12, 1, RepoWatchModeAuto))
-	AssertCount(t, &Watch{UserID: 12, RepoID: 1}, 1)
-	AssertCount(t, &Watch{UserID: 12, RepoID: 1, Mode: RepoWatchModeAuto}, 1)
+	db.AssertCount(t, &Watch{UserID: 12, RepoID: 1}, 1)
+	db.AssertCount(t, &Watch{UserID: 12, RepoID: 1, Mode: RepoWatchModeAuto}, 1)
 
 	assert.NoError(t, WatchRepoMode(12, 1, RepoWatchModeNormal))
-	AssertCount(t, &Watch{UserID: 12, RepoID: 1}, 1)
-	AssertCount(t, &Watch{UserID: 12, RepoID: 1, Mode: RepoWatchModeNormal}, 1)
+	db.AssertCount(t, &Watch{UserID: 12, RepoID: 1}, 1)
+	db.AssertCount(t, &Watch{UserID: 12, RepoID: 1, Mode: RepoWatchModeNormal}, 1)
 
 	assert.NoError(t, WatchRepoMode(12, 1, RepoWatchModeDont))
-	AssertCount(t, &Watch{UserID: 12, RepoID: 1}, 1)
-	AssertCount(t, &Watch{UserID: 12, RepoID: 1, Mode: RepoWatchModeDont}, 1)
+	db.AssertCount(t, &Watch{UserID: 12, RepoID: 1}, 1)
+	db.AssertCount(t, &Watch{UserID: 12, RepoID: 1, Mode: RepoWatchModeDont}, 1)
 
 	assert.NoError(t, WatchRepoMode(12, 1, RepoWatchModeNone))
-	AssertCount(t, &Watch{UserID: 12, RepoID: 1}, 0)
+	db.AssertCount(t, &Watch{UserID: 12, RepoID: 1}, 0)
 }
diff --git a/models/review.go b/models/review.go
index ff5c21e52..ed656f497 100644
--- a/models/review.go
+++ b/models/review.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/timeutil"
 
@@ -77,7 +78,11 @@ type Review struct {
 	Comments []*Comment `xorm:"-"`
 }
 
-func (r *Review) loadCodeComments(e Engine) (err error) {
+func init() {
+	db.RegisterModel(new(Review))
+}
+
+func (r *Review) loadCodeComments(e db.Engine) (err error) {
 	if r.CodeComments != nil {
 		return
 	}
@@ -90,10 +95,10 @@ func (r *Review) loadCodeComments(e Engine) (err error) {
 
 // LoadCodeComments loads CodeComments
 func (r *Review) LoadCodeComments() error {
-	return r.loadCodeComments(x)
+	return r.loadCodeComments(db.DefaultContext().Engine())
 }
 
-func (r *Review) loadIssue(e Engine) (err error) {
+func (r *Review) loadIssue(e db.Engine) (err error) {
 	if r.Issue != nil {
 		return
 	}
@@ -101,7 +106,7 @@ func (r *Review) loadIssue(e Engine) (err error) {
 	return
 }
 
-func (r *Review) loadReviewer(e Engine) (err error) {
+func (r *Review) loadReviewer(e db.Engine) (err error) {
 	if r.ReviewerID == 0 || r.Reviewer != nil {
 		return
 	}
@@ -109,7 +114,7 @@ func (r *Review) loadReviewer(e Engine) (err error) {
 	return
 }
 
-func (r *Review) loadReviewerTeam(e Engine) (err error) {
+func (r *Review) loadReviewerTeam(e db.Engine) (err error) {
 	if r.ReviewerTeamID == 0 || r.ReviewerTeam != nil {
 		return
 	}
@@ -120,15 +125,15 @@ func (r *Review) loadReviewerTeam(e Engine) (err error) {
 
 // LoadReviewer loads reviewer
 func (r *Review) LoadReviewer() error {
-	return r.loadReviewer(x)
+	return r.loadReviewer(db.DefaultContext().Engine())
 }
 
 // LoadReviewerTeam loads reviewer team
 func (r *Review) LoadReviewerTeam() error {
-	return r.loadReviewerTeam(x)
+	return r.loadReviewerTeam(db.DefaultContext().Engine())
 }
 
-func (r *Review) loadAttributes(e Engine) (err error) {
+func (r *Review) loadAttributes(e db.Engine) (err error) {
 	if err = r.loadIssue(e); err != nil {
 		return
 	}
@@ -146,10 +151,10 @@ func (r *Review) loadAttributes(e Engine) (err error) {
 
 // LoadAttributes loads all attributes except CodeComments
 func (r *Review) LoadAttributes() error {
-	return r.loadAttributes(x)
+	return r.loadAttributes(db.DefaultContext().Engine())
 }
 
-func getReviewByID(e Engine, id int64) (*Review, error) {
+func getReviewByID(e db.Engine, id int64) (*Review, error) {
 	review := new(Review)
 	if has, err := e.ID(id).Get(review); err != nil {
 		return nil, err
@@ -162,7 +167,7 @@ func getReviewByID(e Engine, id int64) (*Review, error) {
 
 // GetReviewByID returns the review by the given ID
 func GetReviewByID(id int64) (*Review, error) {
-	return getReviewByID(x, id)
+	return getReviewByID(db.DefaultContext().Engine(), id)
 }
 
 // FindReviewOptions represent possible filters to find reviews
@@ -191,7 +196,7 @@ func (opts *FindReviewOptions) toCond() builder.Cond {
 	return cond
 }
 
-func findReviews(e Engine, opts FindReviewOptions) ([]*Review, error) {
+func findReviews(e db.Engine, opts FindReviewOptions) ([]*Review, error) {
 	reviews := make([]*Review, 0, 10)
 	sess := e.Where(opts.toCond())
 	if opts.Page > 0 {
@@ -205,12 +210,12 @@ func findReviews(e Engine, opts FindReviewOptions) ([]*Review, error) {
 
 // FindReviews returns reviews passing FindReviewOptions
 func FindReviews(opts FindReviewOptions) ([]*Review, error) {
-	return findReviews(x, opts)
+	return findReviews(db.DefaultContext().Engine(), opts)
 }
 
 // CountReviews returns count of reviews passing FindReviewOptions
 func CountReviews(opts FindReviewOptions) (int64, error) {
-	return x.Where(opts.toCond()).Count(&Review{})
+	return db.DefaultContext().Engine().Where(opts.toCond()).Count(&Review{})
 }
 
 // CreateReviewOptions represent the options to create a review. Type, Issue and Reviewer are required.
@@ -227,10 +232,10 @@ type CreateReviewOptions struct {
 
 // IsOfficialReviewer check if at least one of the provided reviewers can make official reviews in issue (counts towards required approvals)
 func IsOfficialReviewer(issue *Issue, reviewers ...*User) (bool, error) {
-	return isOfficialReviewer(x, issue, reviewers...)
+	return isOfficialReviewer(db.DefaultContext().Engine(), issue, reviewers...)
 }
 
-func isOfficialReviewer(e Engine, issue *Issue, reviewers ...*User) (bool, error) {
+func isOfficialReviewer(e db.Engine, issue *Issue, reviewers ...*User) (bool, error) {
 	pr, err := getPullRequestByIssueID(e, issue.ID)
 	if err != nil {
 		return false, err
@@ -254,10 +259,10 @@ func isOfficialReviewer(e Engine, issue *Issue, reviewers ...*User) (bool, error
 
 // IsOfficialReviewerTeam check if reviewer in this team can make official reviews in issue (counts towards required approvals)
 func IsOfficialReviewerTeam(issue *Issue, team *Team) (bool, error) {
-	return isOfficialReviewerTeam(x, issue, team)
+	return isOfficialReviewerTeam(db.DefaultContext().Engine(), issue, team)
 }
 
-func isOfficialReviewerTeam(e Engine, issue *Issue, team *Team) (bool, error) {
+func isOfficialReviewerTeam(e db.Engine, issue *Issue, team *Team) (bool, error) {
 	pr, err := getPullRequestByIssueID(e, issue.ID)
 	if err != nil {
 		return false, err
@@ -276,7 +281,7 @@ func isOfficialReviewerTeam(e Engine, issue *Issue, team *Team) (bool, error) {
 	return base.Int64sContains(pr.ProtectedBranch.ApprovalsWhitelistTeamIDs, team.ID), nil
 }
 
-func createReview(e Engine, opts CreateReviewOptions) (*Review, error) {
+func createReview(e db.Engine, opts CreateReviewOptions) (*Review, error) {
 	review := &Review{
 		Type:         opts.Type,
 		Issue:        opts.Issue,
@@ -305,10 +310,10 @@ func createReview(e Engine, opts CreateReviewOptions) (*Review, error) {
 
 // CreateReview creates a new review based on opts
 func CreateReview(opts CreateReviewOptions) (*Review, error) {
-	return createReview(x, opts)
+	return createReview(db.DefaultContext().Engine(), opts)
 }
 
-func getCurrentReview(e Engine, reviewer *User, issue *Issue) (*Review, error) {
+func getCurrentReview(e db.Engine, reviewer *User, issue *Issue) (*Review, error) {
 	if reviewer == nil {
 		return nil, nil
 	}
@@ -330,12 +335,12 @@ func getCurrentReview(e Engine, reviewer *User, issue *Issue) (*Review, error) {
 
 // ReviewExists returns whether a review exists for a particular line of code in the PR
 func ReviewExists(issue *Issue, treePath string, line int64) (bool, error) {
-	return x.Cols("id").Exist(&Comment{IssueID: issue.ID, TreePath: treePath, Line: line, Type: CommentTypeCode})
+	return db.DefaultContext().Engine().Cols("id").Exist(&Comment{IssueID: issue.ID, TreePath: treePath, Line: line, Type: CommentTypeCode})
 }
 
 // GetCurrentReview returns the current pending review of reviewer for given issue
 func GetCurrentReview(reviewer *User, issue *Issue) (*Review, error) {
-	return getCurrentReview(x, reviewer, issue)
+	return getCurrentReview(db.DefaultContext().Engine(), reviewer, issue)
 }
 
 // ContentEmptyErr represents an content empty error
@@ -353,7 +358,7 @@ func IsContentEmptyErr(err error) bool {
 
 // SubmitReview creates a review out of the existing pending review or creates a new one if no pending review exist
 func SubmitReview(doer *User, issue *Issue, reviewType ReviewType, content, commitID string, stale bool, attachmentUUIDs []string) (*Review, *Comment, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return nil, nil, err
@@ -465,7 +470,7 @@ func SubmitReview(doer *User, issue *Issue, reviewType ReviewType, content, comm
 func GetReviewersByIssueID(issueID int64) ([]*Review, error) {
 	reviews := make([]*Review, 0, 10)
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return nil, err
@@ -497,7 +502,7 @@ func GetReviewersFromOriginalAuthorsByIssueID(issueID int64) ([]*Review, error)
 	reviews := make([]*Review, 0, 10)
 
 	// Get latest review of each reviewer, sorted in order they were made
-	if err := x.SQL("SELECT * FROM review WHERE id IN (SELECT max(id) as id FROM review WHERE issue_id = ? AND reviewer_team_id = 0 AND type in (?, ?, ?) AND original_author_id <> 0 GROUP BY issue_id, original_author_id) ORDER BY review.updated_unix ASC",
+	if err := db.DefaultContext().Engine().SQL("SELECT * FROM review WHERE id IN (SELECT max(id) as id FROM review WHERE issue_id = ? AND reviewer_team_id = 0 AND type in (?, ?, ?) AND original_author_id <> 0 GROUP BY issue_id, original_author_id) ORDER BY review.updated_unix ASC",
 		issueID, ReviewTypeApprove, ReviewTypeReject, ReviewTypeRequest).
 		Find(&reviews); err != nil {
 		return nil, err
@@ -508,10 +513,10 @@ func GetReviewersFromOriginalAuthorsByIssueID(issueID int64) ([]*Review, error)
 
 // GetReviewByIssueIDAndUserID get the latest review of reviewer for a pull request
 func GetReviewByIssueIDAndUserID(issueID, userID int64) (*Review, error) {
-	return getReviewByIssueIDAndUserID(x, issueID, userID)
+	return getReviewByIssueIDAndUserID(db.DefaultContext().Engine(), issueID, userID)
 }
 
-func getReviewByIssueIDAndUserID(e Engine, issueID, userID int64) (*Review, error) {
+func getReviewByIssueIDAndUserID(e db.Engine, issueID, userID int64) (*Review, error) {
 	review := new(Review)
 
 	has, err := e.SQL("SELECT * FROM review WHERE id IN (SELECT max(id) as id FROM review WHERE issue_id = ? AND reviewer_id = ? AND original_author_id = 0 AND type in (?, ?, ?))",
@@ -530,10 +535,10 @@ func getReviewByIssueIDAndUserID(e Engine, issueID, userID int64) (*Review, erro
 
 // GetTeamReviewerByIssueIDAndTeamID get the latest review requst of reviewer team for a pull request
 func GetTeamReviewerByIssueIDAndTeamID(issueID, teamID int64) (review *Review, err error) {
-	return getTeamReviewerByIssueIDAndTeamID(x, issueID, teamID)
+	return getTeamReviewerByIssueIDAndTeamID(db.DefaultContext().Engine(), issueID, teamID)
 }
 
-func getTeamReviewerByIssueIDAndTeamID(e Engine, issueID, teamID int64) (review *Review, err error) {
+func getTeamReviewerByIssueIDAndTeamID(e db.Engine, issueID, teamID int64) (review *Review, err error) {
 	review = new(Review)
 
 	has := false
@@ -552,14 +557,14 @@ func getTeamReviewerByIssueIDAndTeamID(e Engine, issueID, teamID int64) (review
 
 // MarkReviewsAsStale marks existing reviews as stale
 func MarkReviewsAsStale(issueID int64) (err error) {
-	_, err = x.Exec("UPDATE `review` SET stale=? WHERE issue_id=?", true, issueID)
+	_, err = db.DefaultContext().Engine().Exec("UPDATE `review` SET stale=? WHERE issue_id=?", true, issueID)
 
 	return
 }
 
 // MarkReviewsAsNotStale marks existing reviews as not stale for a giving commit SHA
 func MarkReviewsAsNotStale(issueID int64, commitID string) (err error) {
-	_, err = x.Exec("UPDATE `review` SET stale=? WHERE issue_id=? AND commit_id=?", false, issueID, commitID)
+	_, err = db.DefaultContext().Engine().Exec("UPDATE `review` SET stale=? WHERE issue_id=? AND commit_id=?", false, issueID, commitID)
 
 	return
 }
@@ -576,14 +581,14 @@ func DismissReview(review *Review, isDismiss bool) (err error) {
 		return ErrReviewNotExist{}
 	}
 
-	_, err = x.ID(review.ID).Cols("dismissed").Update(review)
+	_, err = db.DefaultContext().Engine().ID(review.ID).Cols("dismissed").Update(review)
 
 	return
 }
 
 // InsertReviews inserts review and review comments
 func InsertReviews(reviews []*Review) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	if err := sess.Begin(); err != nil {
@@ -625,7 +630,7 @@ func InsertReviews(reviews []*Review) error {
 
 // AddReviewRequest add a review request from one reviewer
 func AddReviewRequest(issue *Issue, reviewer, doer *User) (*Comment, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return nil, err
@@ -679,7 +684,7 @@ func AddReviewRequest(issue *Issue, reviewer, doer *User) (*Comment, error) {
 
 // RemoveReviewRequest remove a review request from one reviewer
 func RemoveReviewRequest(issue *Issue, reviewer, doer *User) (*Comment, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return nil, err
@@ -732,7 +737,7 @@ func RemoveReviewRequest(issue *Issue, reviewer, doer *User) (*Comment, error) {
 
 // AddTeamReviewRequest add a review request from one team
 func AddTeamReviewRequest(issue *Issue, reviewer *Team, doer *User) (*Comment, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return nil, err
@@ -791,7 +796,7 @@ func AddTeamReviewRequest(issue *Issue, reviewer *Team, doer *User) (*Comment, e
 
 // RemoveTeamReviewRequest remove a review request from one team
 func RemoveTeamReviewRequest(issue *Issue, reviewer *Team, doer *User) (*Comment, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return nil, err
@@ -859,7 +864,7 @@ func MarkConversation(comment *Comment, doer *User, isResolve bool) (err error)
 			return nil
 		}
 
-		if _, err = x.Exec("UPDATE `comment` SET resolve_doer_id=? WHERE id=?", doer.ID, comment.ID); err != nil {
+		if _, err = db.DefaultContext().Engine().Exec("UPDATE `comment` SET resolve_doer_id=? WHERE id=?", doer.ID, comment.ID); err != nil {
 			return err
 		}
 	} else {
@@ -867,7 +872,7 @@ func MarkConversation(comment *Comment, doer *User, isResolve bool) (err error)
 			return nil
 		}
 
-		if _, err = x.Exec("UPDATE `comment` SET resolve_doer_id=? WHERE id=?", 0, comment.ID); err != nil {
+		if _, err = db.DefaultContext().Engine().Exec("UPDATE `comment` SET resolve_doer_id=? WHERE id=?", 0, comment.ID); err != nil {
 			return err
 		}
 	}
@@ -909,7 +914,7 @@ func CanMarkConversation(issue *Issue, doer *User) (permResult bool, err error)
 
 // DeleteReview delete a review and it's code comments
 func DeleteReview(r *Review) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	if err := sess.Begin(); err != nil {
@@ -963,7 +968,7 @@ func (r *Review) GetCodeCommentsCount() int {
 		conds = conds.And(builder.Eq{"invalidated": false})
 	}
 
-	count, err := x.Where(conds).Count(new(Comment))
+	count, err := db.DefaultContext().Engine().Where(conds).Count(new(Comment))
 	if err != nil {
 		return 0
 	}
@@ -978,7 +983,7 @@ func (r *Review) HTMLURL() string {
 		ReviewID: r.ID,
 	}
 	comment := new(Comment)
-	has, err := x.Where(opts.toConds()).Get(comment)
+	has, err := db.DefaultContext().Engine().Where(opts.toConds()).Get(comment)
 	if err != nil || !has {
 		return ""
 	}
diff --git a/models/review_test.go b/models/review_test.go
index accc18419..c809a3d66 100644
--- a/models/review_test.go
+++ b/models/review_test.go
@@ -7,11 +7,12 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestGetReviewByID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	review, err := GetReviewByID(1)
 	assert.NoError(t, err)
 	assert.Equal(t, "Demo Review", review.Content)
@@ -23,23 +24,23 @@ func TestGetReviewByID(t *testing.T) {
 }
 
 func TestReview_LoadAttributes(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	review := AssertExistsAndLoadBean(t, &Review{ID: 1}).(*Review)
+	assert.NoError(t, db.PrepareTestDatabase())
+	review := db.AssertExistsAndLoadBean(t, &Review{ID: 1}).(*Review)
 	assert.NoError(t, review.LoadAttributes())
 	assert.NotNil(t, review.Issue)
 	assert.NotNil(t, review.Reviewer)
 
-	invalidReview1 := AssertExistsAndLoadBean(t, &Review{ID: 2}).(*Review)
+	invalidReview1 := db.AssertExistsAndLoadBean(t, &Review{ID: 2}).(*Review)
 	assert.Error(t, invalidReview1.LoadAttributes())
 
-	invalidReview2 := AssertExistsAndLoadBean(t, &Review{ID: 3}).(*Review)
+	invalidReview2 := db.AssertExistsAndLoadBean(t, &Review{ID: 3}).(*Review)
 	assert.Error(t, invalidReview2.LoadAttributes())
 }
 
 func TestReview_LoadCodeComments(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	review := AssertExistsAndLoadBean(t, &Review{ID: 4}).(*Review)
+	review := db.AssertExistsAndLoadBean(t, &Review{ID: 4}).(*Review)
 	assert.NoError(t, review.LoadAttributes())
 	assert.NoError(t, review.LoadCodeComments())
 	assert.Len(t, review.CodeComments, 1)
@@ -56,7 +57,7 @@ func TestReviewType_Icon(t *testing.T) {
 }
 
 func TestFindReviews(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	reviews, err := FindReviews(FindReviewOptions{
 		Type:       ReviewTypeApprove,
 		IssueID:    2,
@@ -68,9 +69,9 @@ func TestFindReviews(t *testing.T) {
 }
 
 func TestGetCurrentReview(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	issue := AssertExistsAndLoadBean(t, &Issue{ID: 2}).(*Issue)
-	user := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	issue := db.AssertExistsAndLoadBean(t, &Issue{ID: 2}).(*Issue)
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 
 	review, err := GetCurrentReview(user, issue)
 	assert.NoError(t, err)
@@ -78,7 +79,7 @@ func TestGetCurrentReview(t *testing.T) {
 	assert.Equal(t, ReviewTypePending, review.Type)
 	assert.Equal(t, "Pending Review", review.Content)
 
-	user2 := AssertExistsAndLoadBean(t, &User{ID: 7}).(*User)
+	user2 := db.AssertExistsAndLoadBean(t, &User{ID: 7}).(*User)
 	review2, err := GetCurrentReview(user2, issue)
 	assert.Error(t, err)
 	assert.True(t, IsErrReviewNotExist(err))
@@ -86,10 +87,10 @@ func TestGetCurrentReview(t *testing.T) {
 }
 
 func TestCreateReview(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	issue := AssertExistsAndLoadBean(t, &Issue{ID: 2}).(*Issue)
-	user := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	issue := db.AssertExistsAndLoadBean(t, &Issue{ID: 2}).(*Issue)
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 
 	review, err := CreateReview(CreateReviewOptions{
 		Content:  "New Review",
@@ -99,16 +100,16 @@ func TestCreateReview(t *testing.T) {
 	})
 	assert.NoError(t, err)
 	assert.Equal(t, "New Review", review.Content)
-	AssertExistsAndLoadBean(t, &Review{Content: "New Review"})
+	db.AssertExistsAndLoadBean(t, &Review{Content: "New Review"})
 }
 
 func TestGetReviewersByIssueID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	issue := AssertExistsAndLoadBean(t, &Issue{ID: 3}).(*Issue)
-	user2 := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
-	user3 := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
-	user4 := AssertExistsAndLoadBean(t, &User{ID: 4}).(*User)
+	issue := db.AssertExistsAndLoadBean(t, &Issue{ID: 3}).(*Issue)
+	user2 := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user3 := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	user4 := db.AssertExistsAndLoadBean(t, &User{ID: 4}).(*User)
 
 	expectedReviews := []*Review{}
 	expectedReviews = append(expectedReviews,
@@ -143,45 +144,45 @@ func TestGetReviewersByIssueID(t *testing.T) {
 }
 
 func TestDismissReview(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	rejectReviewExample := AssertExistsAndLoadBean(t, &Review{ID: 9}).(*Review)
-	requestReviewExample := AssertExistsAndLoadBean(t, &Review{ID: 11}).(*Review)
-	approveReviewExample := AssertExistsAndLoadBean(t, &Review{ID: 8}).(*Review)
+	rejectReviewExample := db.AssertExistsAndLoadBean(t, &Review{ID: 9}).(*Review)
+	requestReviewExample := db.AssertExistsAndLoadBean(t, &Review{ID: 11}).(*Review)
+	approveReviewExample := db.AssertExistsAndLoadBean(t, &Review{ID: 8}).(*Review)
 	assert.False(t, rejectReviewExample.Dismissed)
 	assert.False(t, requestReviewExample.Dismissed)
 	assert.False(t, approveReviewExample.Dismissed)
 
 	assert.NoError(t, DismissReview(rejectReviewExample, true))
-	rejectReviewExample = AssertExistsAndLoadBean(t, &Review{ID: 9}).(*Review)
-	requestReviewExample = AssertExistsAndLoadBean(t, &Review{ID: 11}).(*Review)
+	rejectReviewExample = db.AssertExistsAndLoadBean(t, &Review{ID: 9}).(*Review)
+	requestReviewExample = db.AssertExistsAndLoadBean(t, &Review{ID: 11}).(*Review)
 	assert.True(t, rejectReviewExample.Dismissed)
 	assert.False(t, requestReviewExample.Dismissed)
 
 	assert.NoError(t, DismissReview(requestReviewExample, true))
-	rejectReviewExample = AssertExistsAndLoadBean(t, &Review{ID: 9}).(*Review)
-	requestReviewExample = AssertExistsAndLoadBean(t, &Review{ID: 11}).(*Review)
+	rejectReviewExample = db.AssertExistsAndLoadBean(t, &Review{ID: 9}).(*Review)
+	requestReviewExample = db.AssertExistsAndLoadBean(t, &Review{ID: 11}).(*Review)
 	assert.True(t, rejectReviewExample.Dismissed)
 	assert.False(t, requestReviewExample.Dismissed)
 	assert.False(t, approveReviewExample.Dismissed)
 
 	assert.NoError(t, DismissReview(requestReviewExample, true))
-	rejectReviewExample = AssertExistsAndLoadBean(t, &Review{ID: 9}).(*Review)
-	requestReviewExample = AssertExistsAndLoadBean(t, &Review{ID: 11}).(*Review)
+	rejectReviewExample = db.AssertExistsAndLoadBean(t, &Review{ID: 9}).(*Review)
+	requestReviewExample = db.AssertExistsAndLoadBean(t, &Review{ID: 11}).(*Review)
 	assert.True(t, rejectReviewExample.Dismissed)
 	assert.False(t, requestReviewExample.Dismissed)
 	assert.False(t, approveReviewExample.Dismissed)
 
 	assert.NoError(t, DismissReview(requestReviewExample, false))
-	rejectReviewExample = AssertExistsAndLoadBean(t, &Review{ID: 9}).(*Review)
-	requestReviewExample = AssertExistsAndLoadBean(t, &Review{ID: 11}).(*Review)
+	rejectReviewExample = db.AssertExistsAndLoadBean(t, &Review{ID: 9}).(*Review)
+	requestReviewExample = db.AssertExistsAndLoadBean(t, &Review{ID: 11}).(*Review)
 	assert.True(t, rejectReviewExample.Dismissed)
 	assert.False(t, requestReviewExample.Dismissed)
 	assert.False(t, approveReviewExample.Dismissed)
 
 	assert.NoError(t, DismissReview(requestReviewExample, false))
-	rejectReviewExample = AssertExistsAndLoadBean(t, &Review{ID: 9}).(*Review)
-	requestReviewExample = AssertExistsAndLoadBean(t, &Review{ID: 11}).(*Review)
+	rejectReviewExample = db.AssertExistsAndLoadBean(t, &Review{ID: 9}).(*Review)
+	requestReviewExample = db.AssertExistsAndLoadBean(t, &Review{ID: 11}).(*Review)
 	assert.True(t, rejectReviewExample.Dismissed)
 	assert.False(t, requestReviewExample.Dismissed)
 	assert.False(t, approveReviewExample.Dismissed)
diff --git a/models/session.go b/models/session.go
index b2e4837be..9a0c71fdd 100644
--- a/models/session.go
+++ b/models/session.go
@@ -7,6 +7,7 @@ package models
 import (
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/timeutil"
 )
 
@@ -17,9 +18,13 @@ type Session struct {
 	Expiry timeutil.TimeStamp // has to be Expiry to match with go-chi/session
 }
 
+func init() {
+	db.RegisterModel(new(Session))
+}
+
 // UpdateSession updates the session with provided id
 func UpdateSession(key string, data []byte) error {
-	_, err := x.ID(key).Update(&Session{
+	_, err := db.DefaultContext().Engine().ID(key).Update(&Session{
 		Data:   data,
 		Expiry: timeutil.TimeStampNow(),
 	})
@@ -31,7 +36,7 @@ func ReadSession(key string) (*Session, error) {
 	session := Session{
 		Key: key,
 	}
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return nil, err
@@ -55,12 +60,12 @@ func ExistSession(key string) (bool, error) {
 	session := Session{
 		Key: key,
 	}
-	return x.Get(&session)
+	return db.DefaultContext().Engine().Get(&session)
 }
 
 // DestroySession destroys a session
 func DestroySession(key string) error {
-	_, err := x.Delete(&Session{
+	_, err := db.DefaultContext().Engine().Delete(&Session{
 		Key: key,
 	})
 	return err
@@ -68,7 +73,7 @@ func DestroySession(key string) error {
 
 // RegenerateSession regenerates a session from the old id
 func RegenerateSession(oldKey, newKey string) (*Session, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return nil, err
@@ -112,11 +117,11 @@ func RegenerateSession(oldKey, newKey string) (*Session, error) {
 
 // CountSessions returns the number of sessions
 func CountSessions() (int64, error) {
-	return x.Count(&Session{})
+	return db.DefaultContext().Engine().Count(&Session{})
 }
 
 // CleanupSessions cleans up expired sessions
 func CleanupSessions(maxLifetime int64) error {
-	_, err := x.Where("expiry <= ?", timeutil.TimeStampNow().Add(-maxLifetime)).Delete(&Session{})
+	_, err := db.DefaultContext().Engine().Where("expiry <= ?", timeutil.TimeStampNow().Add(-maxLifetime)).Delete(&Session{})
 	return err
 }
diff --git a/models/ssh_key.go b/models/ssh_key.go
index a4745d8e3..04be4ce60 100644
--- a/models/ssh_key.go
+++ b/models/ssh_key.go
@@ -10,6 +10,7 @@ import (
 	"strings"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/util"
@@ -47,6 +48,10 @@ type PublicKey struct {
 	HasUsed           bool               `xorm:"-"`
 }
 
+func init() {
+	db.RegisterModel(new(PublicKey))
+}
+
 // AfterLoad is invoked from XORM after setting the values of all fields of this object.
 func (key *PublicKey) AfterLoad() {
 	key.HasUsed = key.UpdatedUnix > key.CreatedUnix
@@ -65,7 +70,7 @@ func (key *PublicKey) AuthorizedString() string {
 	return AuthorizedStringForKey(key)
 }
 
-func addKey(e Engine, key *PublicKey) (err error) {
+func addKey(e db.Engine, key *PublicKey) (err error) {
 	if len(key.Fingerprint) == 0 {
 		key.Fingerprint, err = calcFingerprint(key.Content)
 		if err != nil {
@@ -90,7 +95,7 @@ func AddPublicKey(ownerID int64, name, content string, loginSourceID int64) (*Pu
 		return nil, err
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return nil, err
@@ -129,7 +134,7 @@ func AddPublicKey(ownerID int64, name, content string, loginSourceID int64) (*Pu
 // GetPublicKeyByID returns public key by given ID.
 func GetPublicKeyByID(keyID int64) (*PublicKey, error) {
 	key := new(PublicKey)
-	has, err := x.
+	has, err := db.DefaultContext().Engine().
 		ID(keyID).
 		Get(key)
 	if err != nil {
@@ -140,7 +145,7 @@ func GetPublicKeyByID(keyID int64) (*PublicKey, error) {
 	return key, nil
 }
 
-func searchPublicKeyByContentWithEngine(e Engine, content string) (*PublicKey, error) {
+func searchPublicKeyByContentWithEngine(e db.Engine, content string) (*PublicKey, error) {
 	key := new(PublicKey)
 	has, err := e.
 		Where("content like ?", content+"%").
@@ -156,10 +161,10 @@ func searchPublicKeyByContentWithEngine(e Engine, content string) (*PublicKey, e
 // SearchPublicKeyByContent searches content as prefix (leak e-mail part)
 // and returns public key found.
 func SearchPublicKeyByContent(content string) (*PublicKey, error) {
-	return searchPublicKeyByContentWithEngine(x, content)
+	return searchPublicKeyByContentWithEngine(db.DefaultContext().Engine(), content)
 }
 
-func searchPublicKeyByContentExactWithEngine(e Engine, content string) (*PublicKey, error) {
+func searchPublicKeyByContentExactWithEngine(e db.Engine, content string) (*PublicKey, error) {
 	key := new(PublicKey)
 	has, err := e.
 		Where("content = ?", content).
@@ -175,7 +180,7 @@ func searchPublicKeyByContentExactWithEngine(e Engine, content string) (*PublicK
 // SearchPublicKeyByContentExact searches content
 // and returns public key found.
 func SearchPublicKeyByContentExact(content string) (*PublicKey, error) {
-	return searchPublicKeyByContentExactWithEngine(x, content)
+	return searchPublicKeyByContentExactWithEngine(db.DefaultContext().Engine(), content)
 }
 
 // SearchPublicKey returns a list of public keys matching the provided arguments.
@@ -188,12 +193,12 @@ func SearchPublicKey(uid int64, fingerprint string) ([]*PublicKey, error) {
 	if fingerprint != "" {
 		cond = cond.And(builder.Eq{"fingerprint": fingerprint})
 	}
-	return keys, x.Where(cond).Find(&keys)
+	return keys, db.DefaultContext().Engine().Where(cond).Find(&keys)
 }
 
 // ListPublicKeys returns a list of public keys belongs to given user.
 func ListPublicKeys(uid int64, listOptions ListOptions) ([]*PublicKey, error) {
-	sess := x.Where("owner_id = ? AND type != ?", uid, KeyTypePrincipal)
+	sess := db.DefaultContext().Engine().Where("owner_id = ? AND type != ?", uid, KeyTypePrincipal)
 	if listOptions.Page != 0 {
 		sess = setSessionPagination(sess, &listOptions)
 
@@ -207,14 +212,14 @@ func ListPublicKeys(uid int64, listOptions ListOptions) ([]*PublicKey, error) {
 
 // CountPublicKeys count public keys a user has
 func CountPublicKeys(userID int64) (int64, error) {
-	sess := x.Where("owner_id = ? AND type != ?", userID, KeyTypePrincipal)
+	sess := db.DefaultContext().Engine().Where("owner_id = ? AND type != ?", userID, KeyTypePrincipal)
 	return sess.Count(&PublicKey{})
 }
 
 // ListPublicKeysBySource returns a list of synchronized public keys for a given user and login source.
 func ListPublicKeysBySource(uid, loginSourceID int64) ([]*PublicKey, error) {
 	keys := make([]*PublicKey, 0, 5)
-	return keys, x.
+	return keys, db.DefaultContext().Engine().
 		Where("owner_id = ? AND login_source_id = ?", uid, loginSourceID).
 		Find(&keys)
 }
@@ -223,13 +228,13 @@ func ListPublicKeysBySource(uid, loginSourceID int64) ([]*PublicKey, error) {
 func UpdatePublicKeyUpdated(id int64) error {
 	// Check if key exists before update as affected rows count is unreliable
 	//    and will return 0 affected rows if two updates are made at the same time
-	if cnt, err := x.ID(id).Count(&PublicKey{}); err != nil {
+	if cnt, err := db.DefaultContext().Engine().ID(id).Count(&PublicKey{}); err != nil {
 		return err
 	} else if cnt != 1 {
 		return ErrKeyNotExist{id}
 	}
 
-	_, err := x.ID(id).Cols("updated_unix").Update(&PublicKey{
+	_, err := db.DefaultContext().Engine().ID(id).Cols("updated_unix").Update(&PublicKey{
 		UpdatedUnix: timeutil.TimeStampNow(),
 	})
 	if err != nil {
@@ -239,7 +244,7 @@ func UpdatePublicKeyUpdated(id int64) error {
 }
 
 // deletePublicKeys does the actual key deletion but does not update authorized_keys file.
-func deletePublicKeys(e Engine, keyIDs ...int64) error {
+func deletePublicKeys(e db.Engine, keyIDs ...int64) error {
 	if len(keyIDs) == 0 {
 		return nil
 	}
@@ -328,7 +333,7 @@ func DeletePublicKey(doer *User, id int64) (err error) {
 		return ErrKeyAccessDenied{doer.ID, key.ID, "public"}
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -353,7 +358,7 @@ func DeletePublicKey(doer *User, id int64) (err error) {
 // deleteKeysMarkedForDeletion returns true if ssh keys needs update
 func deleteKeysMarkedForDeletion(keys []string) (bool, error) {
 	// Start session
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return false, err
diff --git a/models/ssh_key_authorized_keys.go b/models/ssh_key_authorized_keys.go
index 5736477a0..e490f2118 100644
--- a/models/ssh_key_authorized_keys.go
+++ b/models/ssh_key_authorized_keys.go
@@ -14,6 +14,7 @@ import (
 	"sync"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
@@ -114,13 +115,13 @@ func appendAuthorizedKeysToFile(keys ...*PublicKey) error {
 }
 
 // RewriteAllPublicKeys removes any authorized key and rewrite all keys from database again.
-// Note: x.Iterate does not get latest data after insert/delete, so we have to call this function
+// Note: db.DefaultContext().Engine().Iterate does not get latest data after insert/delete, so we have to call this function
 // outside any session scope independently.
 func RewriteAllPublicKeys() error {
-	return rewriteAllPublicKeys(x)
+	return rewriteAllPublicKeys(db.DefaultContext().Engine())
 }
 
-func rewriteAllPublicKeys(e Engine) error {
+func rewriteAllPublicKeys(e db.Engine) error {
 	// Don't rewrite key if internal server
 	if setting.SSH.StartBuiltinServer || !setting.SSH.CreateAuthorizedKeysFile {
 		return nil
@@ -178,10 +179,10 @@ func rewriteAllPublicKeys(e Engine) error {
 
 // RegeneratePublicKeys regenerates the authorized_keys file
 func RegeneratePublicKeys(t io.StringWriter) error {
-	return regeneratePublicKeys(x, t)
+	return regeneratePublicKeys(db.DefaultContext().Engine(), t)
 }
 
-func regeneratePublicKeys(e Engine, t io.StringWriter) error {
+func regeneratePublicKeys(e db.Engine, t io.StringWriter) error {
 	if err := e.Where("type != ?", KeyTypePrincipal).Iterate(new(PublicKey), func(idx int, bean interface{}) (err error) {
 		_, err = t.WriteString((bean.(*PublicKey)).AuthorizedString())
 		return err
diff --git a/models/ssh_key_authorized_principals.go b/models/ssh_key_authorized_principals.go
index f90ab267a..c5f7b2178 100644
--- a/models/ssh_key_authorized_principals.go
+++ b/models/ssh_key_authorized_principals.go
@@ -13,6 +13,7 @@ import (
 	"strings"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
@@ -39,13 +40,13 @@ import (
 const authorizedPrincipalsFile = "authorized_principals"
 
 // RewriteAllPrincipalKeys removes any authorized principal and rewrite all keys from database again.
-// Note: x.Iterate does not get latest data after insert/delete, so we have to call this function
+// Note: db.DefaultContext().Engine().Iterate does not get latest data after insert/delete, so we have to call this function
 // outside any session scope independently.
 func RewriteAllPrincipalKeys() error {
-	return rewriteAllPrincipalKeys(x)
+	return rewriteAllPrincipalKeys(db.DefaultContext().Engine())
 }
 
-func rewriteAllPrincipalKeys(e Engine) error {
+func rewriteAllPrincipalKeys(e db.Engine) error {
 	// Don't rewrite key if internal server
 	if setting.SSH.StartBuiltinServer || !setting.SSH.CreateAuthorizedPrincipalsFile {
 		return nil
@@ -101,10 +102,10 @@ func rewriteAllPrincipalKeys(e Engine) error {
 
 // RegeneratePrincipalKeys regenerates the authorized_principals file
 func RegeneratePrincipalKeys(t io.StringWriter) error {
-	return regeneratePrincipalKeys(x, t)
+	return regeneratePrincipalKeys(db.DefaultContext().Engine(), t)
 }
 
-func regeneratePrincipalKeys(e Engine, t io.StringWriter) error {
+func regeneratePrincipalKeys(e db.Engine, t io.StringWriter) error {
 	if err := e.Where("type = ?", KeyTypePrincipal).Iterate(new(PublicKey), func(idx int, bean interface{}) (err error) {
 		_, err = t.WriteString((bean.(*PublicKey)).AuthorizedString())
 		return err
diff --git a/models/ssh_key_deploy.go b/models/ssh_key_deploy.go
index 1631da717..7aa764522 100644
--- a/models/ssh_key_deploy.go
+++ b/models/ssh_key_deploy.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/timeutil"
 	"xorm.io/builder"
 	"xorm.io/xorm"
@@ -60,7 +61,11 @@ func (key *DeployKey) IsReadOnly() bool {
 	return key.Mode == AccessModeRead
 }
 
-func checkDeployKey(e Engine, keyID, repoID int64, name string) error {
+func init() {
+	db.RegisterModel(new(DeployKey))
+}
+
+func checkDeployKey(e db.Engine, keyID, repoID int64, name string) error {
 	// Note: We want error detail, not just true or false here.
 	has, err := e.
 		Where("key_id = ? AND repo_id = ?", keyID, repoID).
@@ -102,7 +107,7 @@ func addDeployKey(e *xorm.Session, keyID, repoID int64, name, fingerprint string
 
 // HasDeployKey returns true if public key is a deploy key of given repository.
 func HasDeployKey(keyID, repoID int64) bool {
-	has, _ := x.
+	has, _ := db.DefaultContext().Engine().
 		Where("key_id = ? AND repo_id = ?", keyID, repoID).
 		Get(new(DeployKey))
 	return has
@@ -120,7 +125,7 @@ func AddDeployKey(repoID int64, name, content string, readOnly bool) (*DeployKey
 		accessMode = AccessModeWrite
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return nil, err
@@ -159,10 +164,10 @@ func AddDeployKey(repoID int64, name, content string, readOnly bool) (*DeployKey
 
 // GetDeployKeyByID returns deploy key by given ID.
 func GetDeployKeyByID(id int64) (*DeployKey, error) {
-	return getDeployKeyByID(x, id)
+	return getDeployKeyByID(db.DefaultContext().Engine(), id)
 }
 
-func getDeployKeyByID(e Engine, id int64) (*DeployKey, error) {
+func getDeployKeyByID(e db.Engine, id int64) (*DeployKey, error) {
 	key := new(DeployKey)
 	has, err := e.ID(id).Get(key)
 	if err != nil {
@@ -175,10 +180,10 @@ func getDeployKeyByID(e Engine, id int64) (*DeployKey, error) {
 
 // GetDeployKeyByRepo returns deploy key by given public key ID and repository ID.
 func GetDeployKeyByRepo(keyID, repoID int64) (*DeployKey, error) {
-	return getDeployKeyByRepo(x, keyID, repoID)
+	return getDeployKeyByRepo(db.DefaultContext().Engine(), keyID, repoID)
 }
 
-func getDeployKeyByRepo(e Engine, keyID, repoID int64) (*DeployKey, error) {
+func getDeployKeyByRepo(e db.Engine, keyID, repoID int64) (*DeployKey, error) {
 	key := &DeployKey{
 		KeyID:  keyID,
 		RepoID: repoID,
@@ -194,19 +199,19 @@ func getDeployKeyByRepo(e Engine, keyID, repoID int64) (*DeployKey, error) {
 
 // UpdateDeployKeyCols updates deploy key information in the specified columns.
 func UpdateDeployKeyCols(key *DeployKey, cols ...string) error {
-	_, err := x.ID(key.ID).Cols(cols...).Update(key)
+	_, err := db.DefaultContext().Engine().ID(key.ID).Cols(cols...).Update(key)
 	return err
 }
 
 // UpdateDeployKey updates deploy key information.
 func UpdateDeployKey(key *DeployKey) error {
-	_, err := x.ID(key.ID).AllCols().Update(key)
+	_, err := db.DefaultContext().Engine().ID(key.ID).AllCols().Update(key)
 	return err
 }
 
 // DeleteDeployKey deletes deploy key from its repository authorized_keys file if needed.
 func DeleteDeployKey(doer *User, id int64) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -217,7 +222,7 @@ func DeleteDeployKey(doer *User, id int64) error {
 	return sess.Commit()
 }
 
-func deleteDeployKey(sess Engine, doer *User, id int64) error {
+func deleteDeployKey(sess db.Engine, doer *User, id int64) error {
 	key, err := getDeployKeyByID(sess, id)
 	if err != nil {
 		if IsErrDeployKeyNotExist(err) {
@@ -288,10 +293,10 @@ func (opt ListDeployKeysOptions) toCond() builder.Cond {
 
 // ListDeployKeys returns a list of deploy keys matching the provided arguments.
 func ListDeployKeys(opts *ListDeployKeysOptions) ([]*DeployKey, error) {
-	return listDeployKeys(x, opts)
+	return listDeployKeys(db.DefaultContext().Engine(), opts)
 }
 
-func listDeployKeys(e Engine, opts *ListDeployKeysOptions) ([]*DeployKey, error) {
+func listDeployKeys(e db.Engine, opts *ListDeployKeysOptions) ([]*DeployKey, error) {
 	sess := e.Where(opts.toCond())
 
 	if opts.Page != 0 {
@@ -307,5 +312,5 @@ func listDeployKeys(e Engine, opts *ListDeployKeysOptions) ([]*DeployKey, error)
 
 // CountDeployKeys returns count deploy keys matching the provided arguments.
 func CountDeployKeys(opts *ListDeployKeysOptions) (int64, error) {
-	return x.Where(opts.toCond()).Count(&DeployKey{})
+	return db.DefaultContext().Engine().Where(opts.toCond()).Count(&DeployKey{})
 }
diff --git a/models/ssh_key_fingerprint.go b/models/ssh_key_fingerprint.go
index 96cc7d9c4..93c455e48 100644
--- a/models/ssh_key_fingerprint.go
+++ b/models/ssh_key_fingerprint.go
@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/process"
 	"code.gitea.io/gitea/modules/setting"
@@ -29,7 +30,7 @@ import (
 
 // checkKeyFingerprint only checks if key fingerprint has been used as public key,
 // it is OK to use same key as deploy key for multiple repositories/users.
-func checkKeyFingerprint(e Engine, fingerprint string) error {
+func checkKeyFingerprint(e db.Engine, fingerprint string) error {
 	has, err := e.Get(&PublicKey{
 		Fingerprint: fingerprint,
 	})
diff --git a/models/ssh_key_principals.go b/models/ssh_key_principals.go
index 481085577..5f95cf74d 100644
--- a/models/ssh_key_principals.go
+++ b/models/ssh_key_principals.go
@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 )
 
@@ -23,7 +24,7 @@ import (
 
 // AddPrincipalKey adds new principal to database and authorized_principals file.
 func AddPrincipalKey(ownerID int64, content string, loginSourceID int64) (*PublicKey, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return nil, err
@@ -60,7 +61,7 @@ func AddPrincipalKey(ownerID int64, content string, loginSourceID int64) (*Publi
 	return key, RewriteAllPrincipalKeys()
 }
 
-func addPrincipalKey(e Engine, key *PublicKey) (err error) {
+func addPrincipalKey(e db.Engine, key *PublicKey) (err error) {
 	// Save Key representing a principal.
 	if _, err = e.Insert(key); err != nil {
 		return err
@@ -112,7 +113,7 @@ func CheckPrincipalKeyString(user *User, content string) (_ string, err error) {
 
 // ListPrincipalKeys returns a list of principals belongs to given user.
 func ListPrincipalKeys(uid int64, listOptions ListOptions) ([]*PublicKey, error) {
-	sess := x.Where("owner_id = ? AND type = ?", uid, KeyTypePrincipal)
+	sess := db.DefaultContext().Engine().Where("owner_id = ? AND type = ?", uid, KeyTypePrincipal)
 	if listOptions.Page != 0 {
 		sess = setSessionPagination(sess, &listOptions)
 
diff --git a/models/star.go b/models/star.go
index f71d39ce2..2d50a002d 100644
--- a/models/star.go
+++ b/models/star.go
@@ -5,6 +5,7 @@
 package models
 
 import (
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/timeutil"
 )
 
@@ -16,9 +17,13 @@ type Star struct {
 	CreatedUnix timeutil.TimeStamp `xorm:"INDEX created"`
 }
 
+func init() {
+	db.RegisterModel(new(Star))
+}
+
 // StarRepo or unstar repository.
 func StarRepo(userID, repoID int64, star bool) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	if err := sess.Begin(); err != nil {
@@ -60,17 +65,17 @@ func StarRepo(userID, repoID int64, star bool) error {
 
 // IsStaring checks if user has starred given repository.
 func IsStaring(userID, repoID int64) bool {
-	return isStaring(x, userID, repoID)
+	return isStaring(db.DefaultContext().Engine(), userID, repoID)
 }
 
-func isStaring(e Engine, userID, repoID int64) bool {
+func isStaring(e db.Engine, userID, repoID int64) bool {
 	has, _ := e.Get(&Star{UID: userID, RepoID: repoID})
 	return has
 }
 
 // GetStargazers returns the users that starred the repo.
 func (repo *Repository) GetStargazers(opts ListOptions) ([]*User, error) {
-	sess := x.Where("star.repo_id = ?", repo.ID).
+	sess := db.DefaultContext().Engine().Where("star.repo_id = ?", repo.ID).
 		Join("LEFT", "star", "`user`.id = star.uid")
 	if opts.Page > 0 {
 		sess = setSessionPagination(sess, &opts)
@@ -88,7 +93,7 @@ func (u *User) GetStarredRepos(private bool, page, pageSize int, orderBy string)
 	if len(orderBy) == 0 {
 		orderBy = "updated_unix DESC"
 	}
-	sess := x.
+	sess := db.DefaultContext().Engine().
 		Join("INNER", "star", "star.repo_id = repository.id").
 		Where("star.uid = ?", u.ID).
 		OrderBy(orderBy)
@@ -108,7 +113,7 @@ func (u *User) GetStarredRepos(private bool, page, pageSize int, orderBy string)
 		return
 	}
 
-	if err = repos.loadAttributes(x); err != nil {
+	if err = repos.loadAttributes(db.DefaultContext().Engine()); err != nil {
 		return
 	}
 
@@ -117,7 +122,7 @@ func (u *User) GetStarredRepos(private bool, page, pageSize int, orderBy string)
 
 // GetStarredRepoCount returns the numbers of repo the user starred.
 func (u *User) GetStarredRepoCount(private bool) (int64, error) {
-	sess := x.
+	sess := db.DefaultContext().Engine().
 		Join("INNER", "star", "star.repo_id = repository.id").
 		Where("star.uid = ?", u.ID)
 
diff --git a/models/star_test.go b/models/star_test.go
index 962923800..c0c0a607b 100644
--- a/models/star_test.go
+++ b/models/star_test.go
@@ -7,32 +7,33 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestStarRepo(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	const userID = 2
 	const repoID = 1
-	AssertNotExistsBean(t, &Star{UID: userID, RepoID: repoID})
+	db.AssertNotExistsBean(t, &Star{UID: userID, RepoID: repoID})
 	assert.NoError(t, StarRepo(userID, repoID, true))
-	AssertExistsAndLoadBean(t, &Star{UID: userID, RepoID: repoID})
+	db.AssertExistsAndLoadBean(t, &Star{UID: userID, RepoID: repoID})
 	assert.NoError(t, StarRepo(userID, repoID, true))
-	AssertExistsAndLoadBean(t, &Star{UID: userID, RepoID: repoID})
+	db.AssertExistsAndLoadBean(t, &Star{UID: userID, RepoID: repoID})
 	assert.NoError(t, StarRepo(userID, repoID, false))
-	AssertNotExistsBean(t, &Star{UID: userID, RepoID: repoID})
+	db.AssertNotExistsBean(t, &Star{UID: userID, RepoID: repoID})
 }
 
 func TestIsStaring(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	assert.True(t, IsStaring(2, 4))
 	assert.False(t, IsStaring(3, 4))
 }
 
 func TestRepository_GetStargazers(t *testing.T) {
 	// repo with stargazers
-	assert.NoError(t, PrepareTestDatabase())
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 4}).(*Repository)
+	assert.NoError(t, db.PrepareTestDatabase())
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 4}).(*Repository)
 	gazers, err := repo.GetStargazers(ListOptions{Page: 0})
 	assert.NoError(t, err)
 	if assert.Len(t, gazers, 1) {
@@ -42,8 +43,8 @@ func TestRepository_GetStargazers(t *testing.T) {
 
 func TestRepository_GetStargazers2(t *testing.T) {
 	// repo with stargazers
-	assert.NoError(t, PrepareTestDatabase())
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 3}).(*Repository)
+	assert.NoError(t, db.PrepareTestDatabase())
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 3}).(*Repository)
 	gazers, err := repo.GetStargazers(ListOptions{Page: 0})
 	assert.NoError(t, err)
 	assert.Len(t, gazers, 0)
@@ -51,9 +52,9 @@ func TestRepository_GetStargazers2(t *testing.T) {
 
 func TestUser_GetStarredRepos(t *testing.T) {
 	// user who has starred repos
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	starred, err := user.GetStarredRepos(false, 1, 10, "")
 	assert.NoError(t, err)
 	if assert.Len(t, starred, 1) {
@@ -70,9 +71,9 @@ func TestUser_GetStarredRepos(t *testing.T) {
 
 func TestUser_GetStarredRepos2(t *testing.T) {
 	// user who has no starred repos
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 	starred, err := user.GetStarredRepos(false, 1, 10, "")
 	assert.NoError(t, err)
 	assert.Len(t, starred, 0)
@@ -83,9 +84,9 @@ func TestUser_GetStarredRepos2(t *testing.T) {
 }
 
 func TestUserGetStarredRepoCount(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	counts, err := user.GetStarredRepoCount(false)
 	assert.NoError(t, err)
 	assert.Equal(t, int64(1), counts)
diff --git a/models/statistic.go b/models/statistic.go
new file mode 100644
index 000000000..715a10e70
--- /dev/null
+++ b/models/statistic.go
@@ -0,0 +1,63 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package models
+
+import "code.gitea.io/gitea/models/db"
+
+// Statistic contains the database statistics
+type Statistic struct {
+	Counter struct {
+		User, Org, PublicKey,
+		Repo, Watch, Star, Action, Access,
+		Issue, IssueClosed, IssueOpen,
+		Comment, Oauth, Follow,
+		Mirror, Release, LoginSource, Webhook,
+		Milestone, Label, HookTask,
+		Team, UpdateTask, Attachment int64
+	}
+}
+
+// GetStatistic returns the database statistics
+func GetStatistic() (stats Statistic) {
+	stats.Counter.User = CountUsers()
+	stats.Counter.Org = CountOrganizations()
+	stats.Counter.PublicKey, _ = db.DefaultContext().Engine().Count(new(PublicKey))
+	stats.Counter.Repo = CountRepositories(true)
+	stats.Counter.Watch, _ = db.DefaultContext().Engine().Count(new(Watch))
+	stats.Counter.Star, _ = db.DefaultContext().Engine().Count(new(Star))
+	stats.Counter.Action, _ = db.DefaultContext().Engine().Count(new(Action))
+	stats.Counter.Access, _ = db.DefaultContext().Engine().Count(new(Access))
+
+	type IssueCount struct {
+		Count    int64
+		IsClosed bool
+	}
+	issueCounts := []IssueCount{}
+
+	_ = db.DefaultContext().Engine().Select("COUNT(*) AS count, is_closed").Table("issue").GroupBy("is_closed").Find(&issueCounts)
+	for _, c := range issueCounts {
+		if c.IsClosed {
+			stats.Counter.IssueClosed = c.Count
+		} else {
+			stats.Counter.IssueOpen = c.Count
+		}
+	}
+
+	stats.Counter.Issue = stats.Counter.IssueClosed + stats.Counter.IssueOpen
+
+	stats.Counter.Comment, _ = db.DefaultContext().Engine().Count(new(Comment))
+	stats.Counter.Oauth = 0
+	stats.Counter.Follow, _ = db.DefaultContext().Engine().Count(new(Follow))
+	stats.Counter.Mirror, _ = db.DefaultContext().Engine().Count(new(Mirror))
+	stats.Counter.Release, _ = db.DefaultContext().Engine().Count(new(Release))
+	stats.Counter.LoginSource = CountLoginSources()
+	stats.Counter.Webhook, _ = db.DefaultContext().Engine().Count(new(Webhook))
+	stats.Counter.Milestone, _ = db.DefaultContext().Engine().Count(new(Milestone))
+	stats.Counter.Label, _ = db.DefaultContext().Engine().Count(new(Label))
+	stats.Counter.HookTask, _ = db.DefaultContext().Engine().Count(new(HookTask))
+	stats.Counter.Team, _ = db.DefaultContext().Engine().Count(new(Team))
+	stats.Counter.Attachment, _ = db.DefaultContext().Engine().Count(new(Attachment))
+	return
+}
diff --git a/models/task.go b/models/task.go
index 7dfcaea2e..a943834b9 100644
--- a/models/task.go
+++ b/models/task.go
@@ -7,6 +7,7 @@ package models
 import (
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/json"
 	migration "code.gitea.io/gitea/modules/migrations/base"
 	"code.gitea.io/gitea/modules/secret"
@@ -36,6 +37,10 @@ type Task struct {
 	Created        timeutil.TimeStamp `xorm:"created"`
 }
 
+func init() {
+	db.RegisterModel(new(Task))
+}
+
 // TranslatableMessage represents JSON struct that can be translated with a Locale
 type TranslatableMessage struct {
 	Format string
@@ -44,10 +49,10 @@ type TranslatableMessage struct {
 
 // LoadRepo loads repository of the task
 func (task *Task) LoadRepo() error {
-	return task.loadRepo(x)
+	return task.loadRepo(db.DefaultContext().Engine())
 }
 
-func (task *Task) loadRepo(e Engine) error {
+func (task *Task) loadRepo(e db.Engine) error {
 	if task.Repo != nil {
 		return nil
 	}
@@ -71,7 +76,7 @@ func (task *Task) LoadDoer() error {
 	}
 
 	var doer User
-	has, err := x.ID(task.DoerID).Get(&doer)
+	has, err := db.DefaultContext().Engine().ID(task.DoerID).Get(&doer)
 	if err != nil {
 		return err
 	} else if !has {
@@ -91,7 +96,7 @@ func (task *Task) LoadOwner() error {
 	}
 
 	var owner User
-	has, err := x.ID(task.OwnerID).Get(&owner)
+	has, err := db.DefaultContext().Engine().ID(task.OwnerID).Get(&owner)
 	if err != nil {
 		return err
 	} else if !has {
@@ -106,7 +111,7 @@ func (task *Task) LoadOwner() error {
 
 // UpdateCols updates some columns
 func (task *Task) UpdateCols(cols ...string) error {
-	_, err := x.ID(task.ID).Cols(cols...).Update(task)
+	_, err := db.DefaultContext().Engine().ID(task.ID).Cols(cols...).Update(task)
 	return err
 }
 
@@ -165,7 +170,7 @@ func GetMigratingTask(repoID int64) (*Task, error) {
 		RepoID: repoID,
 		Type:   structs.TaskTypeMigrateRepo,
 	}
-	has, err := x.Get(&task)
+	has, err := db.DefaultContext().Engine().Get(&task)
 	if err != nil {
 		return nil, err
 	} else if !has {
@@ -181,7 +186,7 @@ func GetMigratingTaskByID(id, doerID int64) (*Task, *migration.MigrateOptions, e
 		DoerID: doerID,
 		Type:   structs.TaskTypeMigrateRepo,
 	}
-	has, err := x.Get(&task)
+	has, err := db.DefaultContext().Engine().Get(&task)
 	if err != nil {
 		return nil, nil, err
 	} else if !has {
@@ -212,16 +217,16 @@ func (opts FindTaskOptions) ToConds() builder.Cond {
 // FindTasks find all tasks
 func FindTasks(opts FindTaskOptions) ([]*Task, error) {
 	tasks := make([]*Task, 0, 10)
-	err := x.Where(opts.ToConds()).Find(&tasks)
+	err := db.DefaultContext().Engine().Where(opts.ToConds()).Find(&tasks)
 	return tasks, err
 }
 
 // CreateTask creates a task on database
 func CreateTask(task *Task) error {
-	return createTask(x, task)
+	return createTask(db.DefaultContext().Engine(), task)
 }
 
-func createTask(e Engine, task *Task) error {
+func createTask(e db.Engine, task *Task) error {
 	_, err := e.Insert(task)
 	return err
 }
@@ -248,7 +253,7 @@ func FinishMigrateTask(task *Task) error {
 	}
 	task.PayloadContent = string(confBytes)
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
diff --git a/models/token.go b/models/token.go
index 9862fabb6..4e1e8f1e8 100644
--- a/models/token.go
+++ b/models/token.go
@@ -7,9 +7,12 @@ package models
 
 import (
 	"crypto/subtle"
+	"fmt"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/base"
+	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/util"
 
@@ -41,6 +44,21 @@ func (t *AccessToken) AfterLoad() {
 	t.HasRecentActivity = t.UpdatedUnix.AddDuration(7*24*time.Hour) > timeutil.TimeStampNow()
 }
 
+func init() {
+	db.RegisterModel(new(AccessToken), func() error {
+		if setting.SuccessfulTokensCacheSize > 0 {
+			var err error
+			successfulAccessTokenCache, err = lru.New(setting.SuccessfulTokensCacheSize)
+			if err != nil {
+				return fmt.Errorf("unable to allocate AccessToken cache: %v", err)
+			}
+		} else {
+			successfulAccessTokenCache = nil
+		}
+		return nil
+	})
+}
+
 // NewAccessToken creates new access token.
 func NewAccessToken(t *AccessToken) error {
 	salt, err := util.RandomString(10)
@@ -51,7 +69,7 @@ func NewAccessToken(t *AccessToken) error {
 	t.Token = base.EncodeSha1(gouuid.New().String())
 	t.TokenHash = hashToken(t.Token, t.TokenSalt)
 	t.TokenLastEight = t.Token[len(t.Token)-8:]
-	_, err = x.Insert(t)
+	_, err = db.DefaultContext().Engine().Insert(t)
 	return err
 }
 
@@ -92,7 +110,7 @@ func GetAccessTokenBySHA(token string) (*AccessToken, error) {
 			TokenLastEight: lastEight,
 		}
 		// Re-get the token from the db in case it has been deleted in the intervening period
-		has, err := x.ID(id).Get(token)
+		has, err := db.DefaultContext().Engine().ID(id).Get(token)
 		if err != nil {
 			return nil, err
 		}
@@ -103,7 +121,7 @@ func GetAccessTokenBySHA(token string) (*AccessToken, error) {
 	}
 
 	var tokens []AccessToken
-	err := x.Table(&AccessToken{}).Where("token_last_eight = ?", lastEight).Find(&tokens)
+	err := db.DefaultContext().Engine().Table(&AccessToken{}).Where("token_last_eight = ?", lastEight).Find(&tokens)
 	if err != nil {
 		return nil, err
 	} else if len(tokens) == 0 {
@@ -124,7 +142,7 @@ func GetAccessTokenBySHA(token string) (*AccessToken, error) {
 
 // AccessTokenByNameExists checks if a token name has been used already by a user.
 func AccessTokenByNameExists(token *AccessToken) (bool, error) {
-	return x.Table("access_token").Where("name = ?", token.Name).And("uid = ?", token.UID).Exist()
+	return db.DefaultContext().Engine().Table("access_token").Where("name = ?", token.Name).And("uid = ?", token.UID).Exist()
 }
 
 // ListAccessTokensOptions contain filter options
@@ -136,7 +154,7 @@ type ListAccessTokensOptions struct {
 
 // ListAccessTokens returns a list of access tokens belongs to given user.
 func ListAccessTokens(opts ListAccessTokensOptions) ([]*AccessToken, error) {
-	sess := x.Where("uid=?", opts.UserID)
+	sess := db.DefaultContext().Engine().Where("uid=?", opts.UserID)
 
 	if len(opts.Name) != 0 {
 		sess = sess.Where("name=?", opts.Name)
@@ -157,13 +175,13 @@ func ListAccessTokens(opts ListAccessTokensOptions) ([]*AccessToken, error) {
 
 // UpdateAccessToken updates information of access token.
 func UpdateAccessToken(t *AccessToken) error {
-	_, err := x.ID(t.ID).AllCols().Update(t)
+	_, err := db.DefaultContext().Engine().ID(t.ID).AllCols().Update(t)
 	return err
 }
 
 // CountAccessTokens count access tokens belongs to given user by options
 func CountAccessTokens(opts ListAccessTokensOptions) (int64, error) {
-	sess := x.Where("uid=?", opts.UserID)
+	sess := db.DefaultContext().Engine().Where("uid=?", opts.UserID)
 	if len(opts.Name) != 0 {
 		sess = sess.Where("name=?", opts.Name)
 	}
@@ -172,7 +190,7 @@ func CountAccessTokens(opts ListAccessTokensOptions) (int64, error) {
 
 // DeleteAccessTokenByID deletes access token by given ID.
 func DeleteAccessTokenByID(id, userID int64) error {
-	cnt, err := x.ID(id).Delete(&AccessToken{
+	cnt, err := db.DefaultContext().Engine().ID(id).Delete(&AccessToken{
 		UID: userID,
 	})
 	if err != nil {
diff --git a/models/token_test.go b/models/token_test.go
index 0f24c7527..21d827ea6 100644
--- a/models/token_test.go
+++ b/models/token_test.go
@@ -7,17 +7,18 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestNewAccessToken(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	token := &AccessToken{
 		UID:  3,
 		Name: "Token C",
 	}
 	assert.NoError(t, NewAccessToken(token))
-	AssertExistsAndLoadBean(t, token)
+	db.AssertExistsAndLoadBean(t, token)
 
 	invalidToken := &AccessToken{
 		ID:   token.ID, // duplicate
@@ -30,7 +31,7 @@ func TestNewAccessToken(t *testing.T) {
 func TestAccessTokenByNameExists(t *testing.T) {
 	name := "Token Gitea"
 
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	token := &AccessToken{
 		UID:  3,
 		Name: name,
@@ -43,7 +44,7 @@ func TestAccessTokenByNameExists(t *testing.T) {
 
 	// Save it to the database
 	assert.NoError(t, NewAccessToken(token))
-	AssertExistsAndLoadBean(t, token)
+	db.AssertExistsAndLoadBean(t, token)
 
 	// This token must be found by name in the DB now
 	exist, err = AccessTokenByNameExists(token)
@@ -63,7 +64,7 @@ func TestAccessTokenByNameExists(t *testing.T) {
 }
 
 func TestGetAccessTokenBySHA(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	token, err := GetAccessTokenBySHA("d2c6c1ba3890b309189a8e618c72a162e4efbf36")
 	assert.NoError(t, err)
 	assert.Equal(t, int64(1), token.UID)
@@ -81,7 +82,7 @@ func TestGetAccessTokenBySHA(t *testing.T) {
 }
 
 func TestListAccessTokens(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	tokens, err := ListAccessTokens(ListAccessTokensOptions{UserID: 1})
 	assert.NoError(t, err)
 	if assert.Len(t, tokens, 2) {
@@ -104,24 +105,24 @@ func TestListAccessTokens(t *testing.T) {
 }
 
 func TestUpdateAccessToken(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	token, err := GetAccessTokenBySHA("4c6f36e6cf498e2a448662f915d932c09c5a146c")
 	assert.NoError(t, err)
 	token.Name = "Token Z"
 
 	assert.NoError(t, UpdateAccessToken(token))
-	AssertExistsAndLoadBean(t, token)
+	db.AssertExistsAndLoadBean(t, token)
 }
 
 func TestDeleteAccessTokenByID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	token, err := GetAccessTokenBySHA("4c6f36e6cf498e2a448662f915d932c09c5a146c")
 	assert.NoError(t, err)
 	assert.Equal(t, int64(1), token.UID)
 
 	assert.NoError(t, DeleteAccessTokenByID(token.ID, 1))
-	AssertNotExistsBean(t, token)
+	db.AssertNotExistsBean(t, token)
 
 	err = DeleteAccessTokenByID(100, 100)
 	assert.Error(t, err)
diff --git a/models/topic.go b/models/topic.go
index 52f9a274a..4b219cc0e 100644
--- a/models/topic.go
+++ b/models/topic.go
@@ -9,16 +9,15 @@ import (
 	"regexp"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/timeutil"
 
 	"xorm.io/builder"
 )
 
 func init() {
-	tables = append(tables,
-		new(Topic),
-		new(RepoTopic),
-	)
+	db.RegisterModel(new(Topic))
+	db.RegisterModel(new(RepoTopic))
 }
 
 var topicPattern = regexp.MustCompile(`^[a-z0-9][a-z0-9-]*$`)
@@ -89,7 +88,7 @@ func SanitizeAndValidateTopics(topics []string) (validTopics, invalidTopics []st
 // GetTopicByName retrieves topic by name
 func GetTopicByName(name string) (*Topic, error) {
 	var topic Topic
-	if has, err := x.Where("name = ?", name).Get(&topic); err != nil {
+	if has, err := db.DefaultContext().Engine().Where("name = ?", name).Get(&topic); err != nil {
 		return nil, err
 	} else if !has {
 		return nil, ErrTopicNotExist{name}
@@ -99,7 +98,7 @@ func GetTopicByName(name string) (*Topic, error) {
 
 // addTopicByNameToRepo adds a topic name to a repo and increments the topic count.
 // Returns topic after the addition
-func addTopicByNameToRepo(e Engine, repoID int64, topicName string) (*Topic, error) {
+func addTopicByNameToRepo(e db.Engine, repoID int64, topicName string) (*Topic, error) {
 	var topic Topic
 	has, err := e.Where("name = ?", topicName).Get(&topic)
 	if err != nil {
@@ -129,7 +128,7 @@ func addTopicByNameToRepo(e Engine, repoID int64, topicName string) (*Topic, err
 }
 
 // removeTopicFromRepo remove a topic from a repo and decrements the topic repo count
-func removeTopicFromRepo(e Engine, repoID int64, topic *Topic) error {
+func removeTopicFromRepo(e db.Engine, repoID int64, topic *Topic) error {
 	topic.RepoCount--
 	if _, err := e.ID(topic.ID).Cols("repo_count").Update(topic); err != nil {
 		return err
@@ -146,7 +145,7 @@ func removeTopicFromRepo(e Engine, repoID int64, topic *Topic) error {
 }
 
 // removeTopicsFromRepo remove all topics from the repo and decrements respective topics repo count
-func removeTopicsFromRepo(e Engine, repoID int64) error {
+func removeTopicsFromRepo(e db.Engine, repoID int64) error {
 	_, err := e.Where(
 		builder.In("id",
 			builder.Select("topic_id").From("repo_topic").Where(builder.Eq{"repo_id": repoID}),
@@ -185,7 +184,7 @@ func (opts *FindTopicOptions) toConds() builder.Cond {
 
 // FindTopics retrieves the topics via FindTopicOptions
 func FindTopics(opts *FindTopicOptions) ([]*Topic, int64, error) {
-	sess := x.Select("topic.*").Where(opts.toConds())
+	sess := db.DefaultContext().Engine().Select("topic.*").Where(opts.toConds())
 	if opts.RepoID > 0 {
 		sess.Join("INNER", "repo_topic", "repo_topic.topic_id = topic.id")
 	}
@@ -199,7 +198,7 @@ func FindTopics(opts *FindTopicOptions) ([]*Topic, int64, error) {
 
 // CountTopics counts the number of topics matching the FindTopicOptions
 func CountTopics(opts *FindTopicOptions) (int64, error) {
-	sess := x.Where(opts.toConds())
+	sess := db.DefaultContext().Engine().Where(opts.toConds())
 	if opts.RepoID > 0 {
 		sess.Join("INNER", "repo_topic", "repo_topic.topic_id = topic.id")
 	}
@@ -208,10 +207,10 @@ func CountTopics(opts *FindTopicOptions) (int64, error) {
 
 // GetRepoTopicByName retrieves topic from name for a repo if it exist
 func GetRepoTopicByName(repoID int64, topicName string) (*Topic, error) {
-	return getRepoTopicByName(x, repoID, topicName)
+	return getRepoTopicByName(db.DefaultContext().Engine(), repoID, topicName)
 }
 
-func getRepoTopicByName(e Engine, repoID int64, topicName string) (*Topic, error) {
+func getRepoTopicByName(e db.Engine, repoID int64, topicName string) (*Topic, error) {
 	cond := builder.NewCond()
 	var topic Topic
 	cond = cond.And(builder.Eq{"repo_topic.repo_id": repoID}).And(builder.Eq{"topic.name": topicName})
@@ -226,7 +225,7 @@ func getRepoTopicByName(e Engine, repoID int64, topicName string) (*Topic, error
 
 // AddTopic adds a topic name to a repository (if it does not already have it)
 func AddTopic(repoID int64, topicName string) (*Topic, error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return nil, err
@@ -273,7 +272,7 @@ func DeleteTopic(repoID int64, topicName string) (*Topic, error) {
 		return nil, nil
 	}
 
-	err = removeTopicFromRepo(x, repoID, topic)
+	err = removeTopicFromRepo(db.DefaultContext().Engine(), repoID, topic)
 
 	return topic, err
 }
@@ -287,7 +286,7 @@ func SaveTopics(repoID int64, topicNames ...string) error {
 		return err
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 
 	if err := sess.Begin(); err != nil {
diff --git a/models/topic_test.go b/models/topic_test.go
index 9386a71e3..9f6352e7e 100644
--- a/models/topic_test.go
+++ b/models/topic_test.go
@@ -7,6 +7,7 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -15,7 +16,7 @@ func TestAddTopic(t *testing.T) {
 	repo1NrOfTopics := 3
 	repo2NrOfTopics := 2
 
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	topics, _, err := FindTopics(&FindTopicOptions{})
 	assert.NoError(t, err)
diff --git a/models/twofactor.go b/models/twofactor.go
index c19c5d120..f2443e04c 100644
--- a/models/twofactor.go
+++ b/models/twofactor.go
@@ -11,6 +11,7 @@ import (
 	"encoding/base64"
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/secret"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/timeutil"
@@ -32,6 +33,10 @@ type TwoFactor struct {
 	UpdatedUnix      timeutil.TimeStamp `xorm:"INDEX updated"`
 }
 
+func init() {
+	db.RegisterModel(new(TwoFactor))
+}
+
 // GenerateScratchToken recreates the scratch token the user is using.
 func (t *TwoFactor) GenerateScratchToken() (string, error) {
 	token, err := util.RandomString(8)
@@ -88,13 +93,13 @@ func (t *TwoFactor) ValidateTOTP(passcode string) (bool, error) {
 
 // NewTwoFactor creates a new two-factor authentication token.
 func NewTwoFactor(t *TwoFactor) error {
-	_, err := x.Insert(t)
+	_, err := db.DefaultContext().Engine().Insert(t)
 	return err
 }
 
 // UpdateTwoFactor updates a two-factor authentication token.
 func UpdateTwoFactor(t *TwoFactor) error {
-	_, err := x.ID(t.ID).AllCols().Update(t)
+	_, err := db.DefaultContext().Engine().ID(t.ID).AllCols().Update(t)
 	return err
 }
 
@@ -102,7 +107,7 @@ func UpdateTwoFactor(t *TwoFactor) error {
 // the user, if any.
 func GetTwoFactorByUID(uid int64) (*TwoFactor, error) {
 	twofa := &TwoFactor{}
-	has, err := x.Where("uid=?", uid).Get(twofa)
+	has, err := db.DefaultContext().Engine().Where("uid=?", uid).Get(twofa)
 	if err != nil {
 		return nil, err
 	} else if !has {
@@ -113,7 +118,7 @@ func GetTwoFactorByUID(uid int64) (*TwoFactor, error) {
 
 // DeleteTwoFactorByID deletes two-factor authentication token by given ID.
 func DeleteTwoFactorByID(id, userID int64) error {
-	cnt, err := x.ID(id).Delete(&TwoFactor{
+	cnt, err := db.DefaultContext().Engine().ID(id).Delete(&TwoFactor{
 		UID: userID,
 	})
 	if err != nil {
diff --git a/models/u2f.go b/models/u2f.go
index 28341906f..66943f8dd 100644
--- a/models/u2f.go
+++ b/models/u2f.go
@@ -5,6 +5,7 @@
 package models
 
 import (
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/timeutil"
 
@@ -22,6 +23,10 @@ type U2FRegistration struct {
 	UpdatedUnix timeutil.TimeStamp `xorm:"INDEX updated"`
 }
 
+func init() {
+	db.RegisterModel(new(U2FRegistration))
+}
+
 // TableName returns a better table name for U2FRegistration
 func (reg U2FRegistration) TableName() string {
 	return "u2f_registration"
@@ -33,14 +38,14 @@ func (reg *U2FRegistration) Parse() (*u2f.Registration, error) {
 	return r, r.UnmarshalBinary(reg.Raw)
 }
 
-func (reg *U2FRegistration) updateCounter(e Engine) error {
+func (reg *U2FRegistration) updateCounter(e db.Engine) error {
 	_, err := e.ID(reg.ID).Cols("counter").Update(reg)
 	return err
 }
 
 // UpdateCounter will update the database value of counter
 func (reg *U2FRegistration) UpdateCounter() error {
-	return reg.updateCounter(x)
+	return reg.updateCounter(db.DefaultContext().Engine())
 }
 
 // U2FRegistrationList is a list of *U2FRegistration
@@ -61,17 +66,17 @@ func (list U2FRegistrationList) ToRegistrations() []u2f.Registration {
 	return regs
 }
 
-func getU2FRegistrationsByUID(e Engine, uid int64) (U2FRegistrationList, error) {
+func getU2FRegistrationsByUID(e db.Engine, uid int64) (U2FRegistrationList, error) {
 	regs := make(U2FRegistrationList, 0)
 	return regs, e.Where("user_id = ?", uid).Find(&regs)
 }
 
 // GetU2FRegistrationByID returns U2F registration by id
 func GetU2FRegistrationByID(id int64) (*U2FRegistration, error) {
-	return getU2FRegistrationByID(x, id)
+	return getU2FRegistrationByID(db.DefaultContext().Engine(), id)
 }
 
-func getU2FRegistrationByID(e Engine, id int64) (*U2FRegistration, error) {
+func getU2FRegistrationByID(e db.Engine, id int64) (*U2FRegistration, error) {
 	reg := new(U2FRegistration)
 	if found, err := e.ID(id).Get(reg); err != nil {
 		return nil, err
@@ -83,10 +88,10 @@ func getU2FRegistrationByID(e Engine, id int64) (*U2FRegistration, error) {
 
 // GetU2FRegistrationsByUID returns all U2F registrations of the given user
 func GetU2FRegistrationsByUID(uid int64) (U2FRegistrationList, error) {
-	return getU2FRegistrationsByUID(x, uid)
+	return getU2FRegistrationsByUID(db.DefaultContext().Engine(), uid)
 }
 
-func createRegistration(e Engine, user *User, name string, reg *u2f.Registration) (*U2FRegistration, error) {
+func createRegistration(e db.Engine, user *User, name string, reg *u2f.Registration) (*U2FRegistration, error) {
 	raw, err := reg.MarshalBinary()
 	if err != nil {
 		return nil, err
@@ -106,15 +111,15 @@ func createRegistration(e Engine, user *User, name string, reg *u2f.Registration
 
 // CreateRegistration will create a new U2FRegistration from the given Registration
 func CreateRegistration(user *User, name string, reg *u2f.Registration) (*U2FRegistration, error) {
-	return createRegistration(x, user, name, reg)
+	return createRegistration(db.DefaultContext().Engine(), user, name, reg)
 }
 
 // DeleteRegistration will delete U2FRegistration
 func DeleteRegistration(reg *U2FRegistration) error {
-	return deleteRegistration(x, reg)
+	return deleteRegistration(db.DefaultContext().Engine(), reg)
 }
 
-func deleteRegistration(e Engine, reg *U2FRegistration) error {
+func deleteRegistration(e db.Engine, reg *U2FRegistration) error {
 	_, err := e.Delete(reg)
 	return err
 }
diff --git a/models/u2f_test.go b/models/u2f_test.go
index 7a38334cf..44eca6953 100644
--- a/models/u2f_test.go
+++ b/models/u2f_test.go
@@ -7,12 +7,13 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 	"github.com/tstranex/u2f"
 )
 
 func TestGetU2FRegistrationByID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	res, err := GetU2FRegistrationByID(1)
 	assert.NoError(t, err)
@@ -24,7 +25,7 @@ func TestGetU2FRegistrationByID(t *testing.T) {
 }
 
 func TestGetU2FRegistrationsByUID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	res, err := GetU2FRegistrationsByUID(1)
 	assert.NoError(t, err)
@@ -37,37 +38,37 @@ func TestU2FRegistration_TableName(t *testing.T) {
 }
 
 func TestU2FRegistration_UpdateCounter(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	reg := AssertExistsAndLoadBean(t, &U2FRegistration{ID: 1}).(*U2FRegistration)
+	assert.NoError(t, db.PrepareTestDatabase())
+	reg := db.AssertExistsAndLoadBean(t, &U2FRegistration{ID: 1}).(*U2FRegistration)
 	reg.Counter = 1
 	assert.NoError(t, reg.UpdateCounter())
-	AssertExistsIf(t, true, &U2FRegistration{ID: 1, Counter: 1})
+	db.AssertExistsIf(t, true, &U2FRegistration{ID: 1, Counter: 1})
 }
 
 func TestU2FRegistration_UpdateLargeCounter(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	reg := AssertExistsAndLoadBean(t, &U2FRegistration{ID: 1}).(*U2FRegistration)
+	assert.NoError(t, db.PrepareTestDatabase())
+	reg := db.AssertExistsAndLoadBean(t, &U2FRegistration{ID: 1}).(*U2FRegistration)
 	reg.Counter = 0xffffffff
 	assert.NoError(t, reg.UpdateCounter())
-	AssertExistsIf(t, true, &U2FRegistration{ID: 1, Counter: 0xffffffff})
+	db.AssertExistsIf(t, true, &U2FRegistration{ID: 1, Counter: 0xffffffff})
 }
 
 func TestCreateRegistration(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	user := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 
 	res, err := CreateRegistration(user, "U2F Created Key", &u2f.Registration{Raw: []byte("Test")})
 	assert.NoError(t, err)
 	assert.Equal(t, "U2F Created Key", res.Name)
 	assert.Equal(t, []byte("Test"), res.Raw)
 
-	AssertExistsIf(t, true, &U2FRegistration{Name: "U2F Created Key", UserID: user.ID})
+	db.AssertExistsIf(t, true, &U2FRegistration{Name: "U2F Created Key", UserID: user.ID})
 }
 
 func TestDeleteRegistration(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	reg := AssertExistsAndLoadBean(t, &U2FRegistration{ID: 1}).(*U2FRegistration)
+	assert.NoError(t, db.PrepareTestDatabase())
+	reg := db.AssertExistsAndLoadBean(t, &U2FRegistration{ID: 1}).(*U2FRegistration)
 
 	assert.NoError(t, DeleteRegistration(reg))
-	AssertNotExistsBean(t, &U2FRegistration{ID: 1})
+	db.AssertNotExistsBean(t, &U2FRegistration{ID: 1})
 }
diff --git a/models/update.go b/models/update.go
index 421c44bb4..0fb73ac89 100644
--- a/models/update.go
+++ b/models/update.go
@@ -7,14 +7,16 @@ package models
 import (
 	"fmt"
 	"strings"
+
+	"code.gitea.io/gitea/models/db"
 )
 
 // PushUpdateDeleteTagsContext updates a number of delete tags with context
-func PushUpdateDeleteTagsContext(ctx DBContext, repo *Repository, tags []string) error {
-	return pushUpdateDeleteTags(ctx.e, repo, tags)
+func PushUpdateDeleteTagsContext(ctx *db.Context, repo *Repository, tags []string) error {
+	return pushUpdateDeleteTags(ctx.Engine(), repo, tags)
 }
 
-func pushUpdateDeleteTags(e Engine, repo *Repository, tags []string) error {
+func pushUpdateDeleteTags(e db.Engine, repo *Repository, tags []string) error {
 	if len(tags) == 0 {
 		return nil
 	}
@@ -53,14 +55,14 @@ func PushUpdateDeleteTag(repo *Repository, tagName string) error {
 		return fmt.Errorf("GetRelease: %v", err)
 	}
 	if rel.IsTag {
-		if _, err = x.ID(rel.ID).Delete(new(Release)); err != nil {
+		if _, err = db.DefaultContext().Engine().ID(rel.ID).Delete(new(Release)); err != nil {
 			return fmt.Errorf("Delete: %v", err)
 		}
 	} else {
 		rel.IsDraft = true
 		rel.NumCommits = 0
 		rel.Sha1 = ""
-		if _, err = x.ID(rel.ID).AllCols().Update(rel); err != nil {
+		if _, err = db.DefaultContext().Engine().ID(rel.ID).AllCols().Update(rel); err != nil {
 			return fmt.Errorf("Update: %v", err)
 		}
 	}
@@ -77,7 +79,7 @@ func SaveOrUpdateTag(repo *Repository, newRel *Release) error {
 
 	if rel == nil {
 		rel = newRel
-		if _, err = x.Insert(rel); err != nil {
+		if _, err = db.DefaultContext().Engine().Insert(rel); err != nil {
 			return fmt.Errorf("InsertOne: %v", err)
 		}
 	} else {
@@ -88,7 +90,7 @@ func SaveOrUpdateTag(repo *Repository, newRel *Release) error {
 		if rel.IsTag && newRel.PublisherID > 0 {
 			rel.PublisherID = newRel.PublisherID
 		}
-		if _, err = x.ID(rel.ID).AllCols().Update(rel); err != nil {
+		if _, err = db.DefaultContext().Engine().ID(rel.ID).AllCols().Update(rel); err != nil {
 			return fmt.Errorf("Update: %v", err)
 		}
 	}
diff --git a/models/upload.go b/models/upload.go
index de2032fb7..ca88c6a39 100644
--- a/models/upload.go
+++ b/models/upload.go
@@ -12,6 +12,7 @@ import (
 	"os"
 	"path"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
@@ -34,6 +35,10 @@ type Upload struct {
 	Name string
 }
 
+func init() {
+	db.RegisterModel(new(Upload))
+}
+
 // UploadLocalPath returns where uploads is stored in local file system based on given UUID.
 func UploadLocalPath(uuid string) string {
 	return path.Join(setting.Repository.Upload.TempPath, uuid[0:1], uuid[1:2], uuid)
@@ -68,7 +73,7 @@ func NewUpload(name string, buf []byte, file multipart.File) (_ *Upload, err err
 		return nil, fmt.Errorf("Copy: %v", err)
 	}
 
-	if _, err := x.Insert(upload); err != nil {
+	if _, err := db.DefaultContext().Engine().Insert(upload); err != nil {
 		return nil, err
 	}
 
@@ -78,7 +83,7 @@ func NewUpload(name string, buf []byte, file multipart.File) (_ *Upload, err err
 // GetUploadByUUID returns the Upload by UUID
 func GetUploadByUUID(uuid string) (*Upload, error) {
 	upload := &Upload{}
-	has, err := x.Where("uuid=?", uuid).Get(upload)
+	has, err := db.DefaultContext().Engine().Where("uuid=?", uuid).Get(upload)
 	if err != nil {
 		return nil, err
 	} else if !has {
@@ -95,7 +100,7 @@ func GetUploadsByUUIDs(uuids []string) ([]*Upload, error) {
 
 	// Silently drop invalid uuids.
 	uploads := make([]*Upload, 0, len(uuids))
-	return uploads, x.In("uuid", uuids).Find(&uploads)
+	return uploads, db.DefaultContext().Engine().In("uuid", uuids).Find(&uploads)
 }
 
 // DeleteUploads deletes multiple uploads
@@ -104,7 +109,7 @@ func DeleteUploads(uploads ...*Upload) (err error) {
 		return nil
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
diff --git a/models/user.go b/models/user.go
index 0e27dae73..a4a3d8316 100644
--- a/models/user.go
+++ b/models/user.go
@@ -20,6 +20,7 @@ import (
 	"time"
 	"unicode/utf8"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
@@ -162,6 +163,10 @@ type User struct {
 	KeepActivityPrivate bool   `xorm:"NOT NULL DEFAULT false"`
 }
 
+func init() {
+	db.RegisterModel(new(User))
+}
+
 // SearchOrganizationsOptions options to filter organizations
 type SearchOrganizationsOptions struct {
 	ListOptions
@@ -231,7 +236,7 @@ func (u *User) GetEmail() string {
 // GetAllUsers returns a slice of all individual users found in DB.
 func GetAllUsers() ([]*User, error) {
 	users := make([]*User, 0)
-	return users, x.OrderBy("id").Where("type = ?", UserTypeIndividual).Find(&users)
+	return users, db.DefaultContext().Engine().OrderBy("id").Where("type = ?", UserTypeIndividual).Find(&users)
 }
 
 // IsLocal returns true if user login type is LoginPlain.
@@ -327,7 +332,7 @@ func (u *User) GenerateEmailActivateCode(email string) string {
 
 // GetFollowers returns range of user's followers.
 func (u *User) GetFollowers(listOptions ListOptions) ([]*User, error) {
-	sess := x.
+	sess := db.DefaultContext().Engine().
 		Where("follow.follow_id=?", u.ID).
 		Join("LEFT", "follow", "`user`.id=follow.user_id")
 
@@ -349,7 +354,7 @@ func (u *User) IsFollowing(followID int64) bool {
 
 // GetFollowing returns range of user's following.
 func (u *User) GetFollowing(listOptions ListOptions) ([]*User, error) {
-	sess := x.
+	sess := db.DefaultContext().Engine().
 		Where("follow.user_id=?", u.ID).
 		Join("LEFT", "follow", "`user`.id=follow.follow_id")
 
@@ -432,10 +437,10 @@ func (u *User) IsPasswordSet() bool {
 
 // IsVisibleToUser check if viewer is able to see user profile
 func (u *User) IsVisibleToUser(viewer *User) bool {
-	return u.isVisibleToUser(x, viewer)
+	return u.isVisibleToUser(db.DefaultContext().Engine(), viewer)
 }
 
-func (u *User) isVisibleToUser(e Engine, viewer *User) bool {
+func (u *User) isVisibleToUser(e db.Engine, viewer *User) bool {
 	if viewer != nil && viewer.IsAdmin {
 		return true
 	}
@@ -460,7 +465,7 @@ func (u *User) isVisibleToUser(e Engine, viewer *User) bool {
 		}
 
 		// Now we need to check if they in some organization together
-		count, err := x.Table("team_user").
+		count, err := db.DefaultContext().Engine().Table("team_user").
 			Where(
 				builder.And(
 					builder.Eq{"uid": viewer.ID},
@@ -503,10 +508,10 @@ func (u *User) IsUserOrgOwner(orgID int64) bool {
 
 // HasMemberWithUserID returns true if user with userID is part of the u organisation.
 func (u *User) HasMemberWithUserID(userID int64) bool {
-	return u.hasMemberWithUserID(x, userID)
+	return u.hasMemberWithUserID(db.DefaultContext().Engine(), userID)
 }
 
-func (u *User) hasMemberWithUserID(e Engine, userID int64) bool {
+func (u *User) hasMemberWithUserID(e db.Engine, userID int64) bool {
 	isMember, err := isOrganizationMember(e, u.ID, userID)
 	if err != nil {
 		log.Error("IsOrganizationMember: %v", err)
@@ -525,7 +530,7 @@ func (u *User) IsPublicMember(orgID int64) bool {
 	return isMember
 }
 
-func (u *User) getOrganizationCount(e Engine) (int64, error) {
+func (u *User) getOrganizationCount(e db.Engine) (int64, error) {
 	return e.
 		Where("uid=?", u.ID).
 		Count(new(OrgUser))
@@ -533,7 +538,7 @@ func (u *User) getOrganizationCount(e Engine) (int64, error) {
 
 // GetOrganizationCount returns count of membership of organization of user.
 func (u *User) GetOrganizationCount() (int64, error) {
-	return u.getOrganizationCount(x)
+	return u.getOrganizationCount(db.DefaultContext().Engine())
 }
 
 // GetRepositories returns repositories that user owns, including private repositories.
@@ -547,7 +552,7 @@ func (u *User) GetRepositories(listOpts ListOptions, names ...string) (err error
 func (u *User) GetRepositoryIDs(units ...UnitType) ([]int64, error) {
 	var ids []int64
 
-	sess := x.Table("repository").Cols("repository.id")
+	sess := db.DefaultContext().Engine().Table("repository").Cols("repository.id")
 
 	if len(units) > 0 {
 		sess = sess.Join("INNER", "repo_unit", "repository.id = repo_unit.repo_id")
@@ -562,7 +567,7 @@ func (u *User) GetRepositoryIDs(units ...UnitType) ([]int64, error) {
 func (u *User) GetActiveRepositoryIDs(units ...UnitType) ([]int64, error) {
 	var ids []int64
 
-	sess := x.Table("repository").Cols("repository.id")
+	sess := db.DefaultContext().Engine().Table("repository").Cols("repository.id")
 
 	if len(units) > 0 {
 		sess = sess.Join("INNER", "repo_unit", "repository.id = repo_unit.repo_id")
@@ -579,7 +584,7 @@ func (u *User) GetActiveRepositoryIDs(units ...UnitType) ([]int64, error) {
 func (u *User) GetOrgRepositoryIDs(units ...UnitType) ([]int64, error) {
 	var ids []int64
 
-	if err := x.Table("repository").
+	if err := db.DefaultContext().Engine().Table("repository").
 		Cols("repository.id").
 		Join("INNER", "team_user", "repository.owner_id = team_user.org_id").
 		Join("INNER", "team_repo", "(? != ? and repository.is_private != ?) OR (team_user.team_id = team_repo.team_id AND repository.id = team_repo.repo_id)", true, u.IsRestricted, true).
@@ -600,7 +605,7 @@ func (u *User) GetOrgRepositoryIDs(units ...UnitType) ([]int64, error) {
 func (u *User) GetActiveOrgRepositoryIDs(units ...UnitType) ([]int64, error) {
 	var ids []int64
 
-	if err := x.Table("repository").
+	if err := db.DefaultContext().Engine().Table("repository").
 		Cols("repository.id").
 		Join("INNER", "team_user", "repository.owner_id = team_user.org_id").
 		Join("INNER", "team_repo", "(? != ? and repository.is_private != ?) OR (team_user.team_id = team_repo.team_id AND repository.id = team_repo.repo_id)", true, u.IsRestricted, true).
@@ -724,7 +729,7 @@ func (u *User) SetEmailNotifications(set string) error {
 	return nil
 }
 
-func isUserExist(e Engine, uid int64, name string) (bool, error) {
+func isUserExist(e db.Engine, uid int64, name string) (bool, error) {
 	if len(name) == 0 {
 		return false, nil
 	}
@@ -738,7 +743,7 @@ func isUserExist(e Engine, uid int64, name string) (bool, error) {
 // If uid is presented, then check will rule out that one,
 // it is used when update a user name in settings page.
 func IsUserExist(uid int64, name string) (bool, error) {
-	return isUserExist(x, uid, name)
+	return isUserExist(db.DefaultContext().Engine(), uid, name)
 }
 
 // GetUserSalt returns a random user salt token.
@@ -874,7 +879,7 @@ func CreateUser(u *User, overwriteDefault ...*CreateUserOverwriteOptions) (err e
 		u.Visibility = overwriteDefault[0].Visibility
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -935,7 +940,7 @@ func CreateUser(u *User, overwriteDefault ...*CreateUserOverwriteOptions) (err e
 	return sess.Commit()
 }
 
-func countUsers(e Engine) int64 {
+func countUsers(e db.Engine) int64 {
 	count, _ := e.
 		Where("type=0").
 		Count(new(User))
@@ -944,7 +949,7 @@ func countUsers(e Engine) int64 {
 
 // CountUsers returns number of users.
 func CountUsers() int64 {
-	return countUsers(x)
+	return countUsers(db.DefaultContext().Engine())
 }
 
 // get user by verify code
@@ -992,7 +997,7 @@ func VerifyActiveEmailCode(code, email string) *EmailAddress {
 
 		if base.VerifyTimeLimitCode(data, minutes, prefix) {
 			emailAddress := &EmailAddress{UID: user.ID, Email: email}
-			if has, _ := x.Get(emailAddress); has {
+			if has, _ := db.DefaultContext().Engine().Get(emailAddress); has {
 				return emailAddress
 			}
 		}
@@ -1007,7 +1012,7 @@ func ChangeUserName(u *User, newUserName string) (err error) {
 		return err
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -1045,7 +1050,7 @@ func ChangeUserName(u *User, newUserName string) (err error) {
 }
 
 // checkDupEmail checks whether there are the same email with the user
-func checkDupEmail(e Engine, u *User) error {
+func checkDupEmail(e db.Engine, u *User) error {
 	u.Email = strings.ToLower(u.Email)
 	has, err := e.
 		Where("id!=?", u.ID).
@@ -1070,7 +1075,7 @@ func validateUser(u *User) error {
 	return ValidateEmail(u.Email)
 }
 
-func updateUser(e Engine, u *User) error {
+func updateUser(e db.Engine, u *User) error {
 	if err := validateUser(u); err != nil {
 		return err
 	}
@@ -1081,15 +1086,15 @@ func updateUser(e Engine, u *User) error {
 
 // UpdateUser updates user's information.
 func UpdateUser(u *User) error {
-	return updateUser(x, u)
+	return updateUser(db.DefaultContext().Engine(), u)
 }
 
 // UpdateUserCols update user according special columns
 func UpdateUserCols(u *User, cols ...string) error {
-	return updateUserCols(x, u, cols...)
+	return updateUserCols(db.DefaultContext().Engine(), u, cols...)
 }
 
-func updateUserCols(e Engine, u *User, cols ...string) error {
+func updateUserCols(e db.Engine, u *User, cols ...string) error {
 	if err := validateUser(u); err != nil {
 		return err
 	}
@@ -1100,7 +1105,7 @@ func updateUserCols(e Engine, u *User, cols ...string) error {
 
 // UpdateUserSetting updates user's settings.
 func UpdateUserSetting(u *User) (err error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -1117,7 +1122,7 @@ func UpdateUserSetting(u *User) (err error) {
 }
 
 // deleteBeans deletes all given beans, beans should contain delete conditions.
-func deleteBeans(e Engine, beans ...interface{}) (err error) {
+func deleteBeans(e db.Engine, beans ...interface{}) (err error) {
 	for i := range beans {
 		if _, err = e.Delete(beans[i]); err != nil {
 			return err
@@ -1126,7 +1131,7 @@ func deleteBeans(e Engine, beans ...interface{}) (err error) {
 	return nil
 }
 
-func deleteUser(e Engine, u *User) error {
+func deleteUser(e db.Engine, u *User) error {
 	// Note: A user owns any repository or belongs to any organization
 	//	cannot perform delete operation.
 
@@ -1306,7 +1311,7 @@ func DeleteUser(u *User) (err error) {
 		return fmt.Errorf("%s is an organization not a user", u.Name)
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -1324,13 +1329,13 @@ func DeleteUser(u *User) (err error) {
 func DeleteInactiveUsers(ctx context.Context, olderThan time.Duration) (err error) {
 	users := make([]*User, 0, 10)
 	if olderThan > 0 {
-		if err = x.
+		if err = db.DefaultContext().Engine().
 			Where("is_active = ? and created_unix < ?", false, time.Now().Add(-olderThan).Unix()).
 			Find(&users); err != nil {
 			return fmt.Errorf("get all inactive users: %v", err)
 		}
 	} else {
-		if err = x.
+		if err = db.DefaultContext().Engine().
 			Where("is_active = ?", false).
 			Find(&users); err != nil {
 			return fmt.Errorf("get all inactive users: %v", err)
@@ -1352,7 +1357,7 @@ func DeleteInactiveUsers(ctx context.Context, olderThan time.Duration) (err erro
 		}
 	}
 
-	_, err = x.
+	_, err = db.DefaultContext().Engine().
 		Where("is_activated = ?", false).
 		Delete(new(EmailAddress))
 	return err
@@ -1363,7 +1368,7 @@ func UserPath(userName string) string {
 	return filepath.Join(setting.RepoRootPath, strings.ToLower(userName))
 }
 
-func getUserByID(e Engine, id int64) (*User, error) {
+func getUserByID(e db.Engine, id int64) (*User, error) {
 	u := new(User)
 	has, err := e.ID(id).Get(u)
 	if err != nil {
@@ -1376,15 +1381,15 @@ func getUserByID(e Engine, id int64) (*User, error) {
 
 // GetUserByID returns the user object by given ID if exists.
 func GetUserByID(id int64) (*User, error) {
-	return getUserByID(x, id)
+	return getUserByID(db.DefaultContext().Engine(), id)
 }
 
 // GetUserByName returns user by given name.
 func GetUserByName(name string) (*User, error) {
-	return getUserByName(x, name)
+	return getUserByName(db.DefaultContext().Engine(), name)
 }
 
-func getUserByName(e Engine, name string) (*User, error) {
+func getUserByName(e db.Engine, name string) (*User, error) {
 	if len(name) == 0 {
 		return nil, ErrUserNotExist{0, name, 0}
 	}
@@ -1401,10 +1406,10 @@ func getUserByName(e Engine, name string) (*User, error) {
 // GetUserEmailsByNames returns a list of e-mails corresponds to names of users
 // that have their email notifications set to enabled or onmention.
 func GetUserEmailsByNames(names []string) []string {
-	return getUserEmailsByNames(x, names)
+	return getUserEmailsByNames(db.DefaultContext().Engine(), names)
 }
 
-func getUserEmailsByNames(e Engine, names []string) []string {
+func getUserEmailsByNames(e db.Engine, names []string) []string {
 	mails := make([]string, 0, len(names))
 	for _, name := range names {
 		u, err := getUserByName(e, name)
@@ -1426,7 +1431,7 @@ func GetMaileableUsersByIDs(ids []int64, isMention bool) ([]*User, error) {
 	ous := make([]*User, 0, len(ids))
 
 	if isMention {
-		return ous, x.In("id", ids).
+		return ous, db.DefaultContext().Engine().In("id", ids).
 			Where("`type` = ?", UserTypeIndividual).
 			And("`prohibit_login` = ?", false).
 			And("`is_active` = ?", true).
@@ -1434,7 +1439,7 @@ func GetMaileableUsersByIDs(ids []int64, isMention bool) ([]*User, error) {
 			Find(&ous)
 	}
 
-	return ous, x.In("id", ids).
+	return ous, db.DefaultContext().Engine().In("id", ids).
 		Where("`type` = ?", UserTypeIndividual).
 		And("`prohibit_login` = ?", false).
 		And("`is_active` = ?", true).
@@ -1445,7 +1450,7 @@ func GetMaileableUsersByIDs(ids []int64, isMention bool) ([]*User, error) {
 // GetUserNamesByIDs returns usernames for all resolved users from a list of Ids.
 func GetUserNamesByIDs(ids []int64) ([]string, error) {
 	unames := make([]string, 0, len(ids))
-	err := x.In("id", ids).
+	err := db.DefaultContext().Engine().In("id", ids).
 		Table("user").
 		Asc("name").
 		Cols("name").
@@ -1459,7 +1464,7 @@ func GetUsersByIDs(ids []int64) (UserList, error) {
 	if len(ids) == 0 {
 		return ous, nil
 	}
-	err := x.In("id", ids).
+	err := db.DefaultContext().Engine().In("id", ids).
 		Asc("name").
 		Find(&ous)
 	return ous, err
@@ -1485,7 +1490,7 @@ func GetUserIDsByNames(names []string, ignoreNonExistent bool) ([]int64, error)
 // GetUsersBySource returns a list of Users for a login source
 func GetUsersBySource(s *LoginSource) ([]*User, error) {
 	var users []*User
-	err := x.Where("login_type = ? AND login_source = ?", s.Type, s.ID).Find(&users)
+	err := db.DefaultContext().Engine().Where("login_type = ? AND login_source = ?", s.Type, s.ID).Find(&users)
 	return users, err
 }
 
@@ -1534,11 +1539,11 @@ func ValidateCommitsWithEmails(oldCommits []*git.Commit) []*UserCommit {
 
 // GetUserByEmail returns the user object by given e-mail if exists.
 func GetUserByEmail(email string) (*User, error) {
-	return GetUserByEmailContext(DefaultDBContext(), email)
+	return GetUserByEmailContext(db.DefaultContext(), email)
 }
 
 // GetUserByEmailContext returns the user object by given e-mail if exists with db context
-func GetUserByEmailContext(ctx DBContext, email string) (*User, error) {
+func GetUserByEmailContext(ctx *db.Context, email string) (*User, error) {
 	if len(email) == 0 {
 		return nil, ErrUserNotExist{0, email, 0}
 	}
@@ -1546,7 +1551,7 @@ func GetUserByEmailContext(ctx DBContext, email string) (*User, error) {
 	email = strings.ToLower(email)
 	// First try to find the user by primary email
 	user := &User{Email: email}
-	has, err := ctx.e.Get(user)
+	has, err := ctx.Engine().Get(user)
 	if err != nil {
 		return nil, err
 	}
@@ -1556,19 +1561,19 @@ func GetUserByEmailContext(ctx DBContext, email string) (*User, error) {
 
 	// Otherwise, check in alternative list for activated email addresses
 	emailAddress := &EmailAddress{Email: email, IsActivated: true}
-	has, err = ctx.e.Get(emailAddress)
+	has, err = ctx.Engine().Get(emailAddress)
 	if err != nil {
 		return nil, err
 	}
 	if has {
-		return getUserByID(ctx.e, emailAddress.UID)
+		return getUserByID(ctx.Engine(), emailAddress.UID)
 	}
 
 	// Finally, if email address is the protected email address:
 	if strings.HasSuffix(email, fmt.Sprintf("@%s", setting.Service.NoReplyAddress)) {
 		username := strings.TrimSuffix(email, fmt.Sprintf("@%s", setting.Service.NoReplyAddress))
 		user := &User{}
-		has, err := ctx.e.Where("lower_name=?", username).Get(user)
+		has, err := ctx.Engine().Where("lower_name=?", username).Get(user)
 		if err != nil {
 			return nil, err
 		}
@@ -1582,7 +1587,7 @@ func GetUserByEmailContext(ctx DBContext, email string) (*User, error) {
 
 // GetUser checks if a user already exists
 func GetUser(user *User) (bool, error) {
-	return x.Get(user)
+	return db.DefaultContext().Engine().Get(user)
 }
 
 // SearchUserOptions contains the options for searching
@@ -1659,7 +1664,7 @@ func (opts *SearchUserOptions) toConds() builder.Cond {
 // it returns results in given range and number of total results.
 func SearchUsers(opts *SearchUserOptions) (users []*User, _ int64, _ error) {
 	cond := opts.toConds()
-	count, err := x.Where(cond).Count(new(User))
+	count, err := db.DefaultContext().Engine().Where(cond).Count(new(User))
 	if err != nil {
 		return nil, 0, fmt.Errorf("Count: %v", err)
 	}
@@ -1668,7 +1673,7 @@ func SearchUsers(opts *SearchUserOptions) (users []*User, _ int64, _ error) {
 		opts.OrderBy = SearchOrderByAlphabetically
 	}
 
-	sess := x.Where(cond).OrderBy(opts.OrderBy.String())
+	sess := db.DefaultContext().Engine().Where(cond).OrderBy(opts.OrderBy.String())
 	if opts.Page != 0 {
 		sess = setSessionPagination(sess, opts)
 	}
@@ -1679,7 +1684,7 @@ func SearchUsers(opts *SearchUserOptions) (users []*User, _ int64, _ error) {
 
 // GetStarredRepos returns the repos starred by a particular user
 func GetStarredRepos(userID int64, private bool, listOptions ListOptions) ([]*Repository, error) {
-	sess := x.Where("star.uid=?", userID).
+	sess := db.DefaultContext().Engine().Where("star.uid=?", userID).
 		Join("LEFT", "star", "`repository`.id=`star`.repo_id")
 	if !private {
 		sess = sess.And("is_private=?", false)
@@ -1698,7 +1703,7 @@ func GetStarredRepos(userID int64, private bool, listOptions ListOptions) ([]*Re
 
 // GetWatchedRepos returns the repos watched by a particular user
 func GetWatchedRepos(userID int64, private bool, listOptions ListOptions) ([]*Repository, int64, error) {
-	sess := x.Where("watch.user_id=?", userID).
+	sess := db.DefaultContext().Engine().Where("watch.user_id=?", userID).
 		And("`watch`.mode<>?", RepoWatchModeDont).
 		Join("LEFT", "watch", "`repository`.id=`watch`.repo_id")
 	if !private {
@@ -1724,7 +1729,7 @@ func IterateUser(f func(user *User) error) error {
 	batchSize := setting.Database.IterateBufferSize
 	for {
 		users := make([]*User, 0, batchSize)
-		if err := x.Limit(batchSize, start).Find(&users); err != nil {
+		if err := db.DefaultContext().Engine().Limit(batchSize, start).Find(&users); err != nil {
 			return err
 		}
 		if len(users) == 0 {
diff --git a/models/user_avatar.go b/models/user_avatar.go
index d336684a2..99e533758 100644
--- a/models/user_avatar.go
+++ b/models/user_avatar.go
@@ -12,6 +12,7 @@ import (
 	"strconv"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/avatar"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -25,10 +26,10 @@ func (u *User) CustomAvatarRelativePath() string {
 
 // GenerateRandomAvatar generates a random avatar for user.
 func (u *User) GenerateRandomAvatar() error {
-	return u.generateRandomAvatar(x)
+	return u.generateRandomAvatar(db.DefaultContext().Engine())
 }
 
-func (u *User) generateRandomAvatar(e Engine) error {
+func (u *User) generateRandomAvatar(e db.Engine) error {
 	seed := u.Email
 	if len(seed) == 0 {
 		seed = u.Name
@@ -124,7 +125,7 @@ func (u *User) UploadAvatar(data []byte) error {
 		return err
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -164,7 +165,7 @@ func (u *User) DeleteAvatar() error {
 
 	u.UseCustomAvatar = false
 	u.Avatar = ""
-	if _, err := x.ID(u.ID).Cols("avatar, use_custom_avatar").Update(u); err != nil {
+	if _, err := db.DefaultContext().Engine().ID(u.ID).Cols("avatar, use_custom_avatar").Update(u); err != nil {
 		return fmt.Errorf("UpdateUser: %v", err)
 	}
 	return nil
diff --git a/models/user_follow.go b/models/user_follow.go
index 8321d9507..ceaaaf910 100644
--- a/models/user_follow.go
+++ b/models/user_follow.go
@@ -5,6 +5,7 @@
 package models
 
 import (
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/timeutil"
 )
 
@@ -16,9 +17,13 @@ type Follow struct {
 	CreatedUnix timeutil.TimeStamp `xorm:"INDEX created"`
 }
 
+func init() {
+	db.RegisterModel(new(Follow))
+}
+
 // IsFollowing returns true if user is following followID.
 func IsFollowing(userID, followID int64) bool {
-	has, _ := x.Get(&Follow{UserID: userID, FollowID: followID})
+	has, _ := db.DefaultContext().Engine().Get(&Follow{UserID: userID, FollowID: followID})
 	return has
 }
 
@@ -28,7 +33,7 @@ func FollowUser(userID, followID int64) (err error) {
 		return nil
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -54,7 +59,7 @@ func UnfollowUser(userID, followID int64) (err error) {
 		return nil
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
diff --git a/models/user_follow_test.go b/models/user_follow_test.go
index a30944f03..ae8faad6f 100644
--- a/models/user_follow_test.go
+++ b/models/user_follow_test.go
@@ -7,24 +7,25 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestIsFollowing(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	assert.True(t, IsFollowing(4, 2))
 	assert.False(t, IsFollowing(2, 4))
-	assert.False(t, IsFollowing(5, NonexistentID))
-	assert.False(t, IsFollowing(NonexistentID, 5))
-	assert.False(t, IsFollowing(NonexistentID, NonexistentID))
+	assert.False(t, IsFollowing(5, db.NonexistentID))
+	assert.False(t, IsFollowing(db.NonexistentID, 5))
+	assert.False(t, IsFollowing(db.NonexistentID, db.NonexistentID))
 }
 
 func TestFollowUser(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	testSuccess := func(followerID, followedID int64) {
 		assert.NoError(t, FollowUser(followerID, followedID))
-		AssertExistsAndLoadBean(t, &Follow{UserID: followerID, FollowID: followedID})
+		db.AssertExistsAndLoadBean(t, &Follow{UserID: followerID, FollowID: followedID})
 	}
 	testSuccess(4, 2)
 	testSuccess(5, 2)
@@ -35,11 +36,11 @@ func TestFollowUser(t *testing.T) {
 }
 
 func TestUnfollowUser(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	testSuccess := func(followerID, followedID int64) {
 		assert.NoError(t, UnfollowUser(followerID, followedID))
-		AssertNotExistsBean(t, &Follow{UserID: followerID, FollowID: followedID})
+		db.AssertNotExistsBean(t, &Follow{UserID: followerID, FollowID: followedID})
 	}
 	testSuccess(4, 2)
 	testSuccess(5, 2)
diff --git a/models/user_heatmap.go b/models/user_heatmap.go
index 306bd1819..e71361263 100644
--- a/models/user_heatmap.go
+++ b/models/user_heatmap.go
@@ -5,6 +5,7 @@
 package models
 
 import (
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/timeutil"
 )
@@ -58,7 +59,7 @@ func getUserHeatmapData(user *User, team *Team, doer *User) ([]*UserHeatmapData,
 		return nil, err
 	}
 
-	return hdata, x.
+	return hdata, db.DefaultContext().Engine().
 		Select(groupBy+" AS timestamp, count(user_id) as contributions").
 		Table("action").
 		Where(cond).
diff --git a/models/user_heatmap_test.go b/models/user_heatmap_test.go
index bdf776665..c40e34159 100644
--- a/models/user_heatmap_test.go
+++ b/models/user_heatmap_test.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/json"
 
 	"github.com/stretchr/testify/assert"
@@ -36,13 +37,13 @@ func TestGetUserHeatmapDataByUser(t *testing.T) {
 		{10, 10, 3, `[{"timestamp":1603009800,"contributions":1},{"timestamp":1603010700,"contributions":2}]`},
 	}
 	// Prepare
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	for i, tc := range testCases {
-		user := AssertExistsAndLoadBean(t, &User{ID: tc.userID}).(*User)
+		user := db.AssertExistsAndLoadBean(t, &User{ID: tc.userID}).(*User)
 
 		doer := &User{ID: tc.doerID}
-		_, err := loadBeanIfExists(doer)
+		_, err := db.LoadBeanIfExists(doer)
 		assert.NoError(t, err)
 		if tc.doerID == 0 {
 			doer = nil
diff --git a/models/user_mail.go b/models/user_mail.go
index f8b084a00..169399bc7 100644
--- a/models/user_mail.go
+++ b/models/user_mail.go
@@ -10,6 +10,7 @@ import (
 	"net/mail"
 	"strings"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
@@ -28,6 +29,10 @@ type EmailAddress struct {
 	IsPrimary   bool `xorm:"DEFAULT(false) NOT NULL"`
 }
 
+func init() {
+	db.RegisterModel(new(EmailAddress))
+}
+
 // BeforeInsert will be invoked by XORM before inserting a record
 func (email *EmailAddress) BeforeInsert() {
 	if email.LowerEmail == "" {
@@ -53,7 +58,7 @@ func ValidateEmail(email string) error {
 // GetEmailAddresses returns all email addresses belongs to given user.
 func GetEmailAddresses(uid int64) ([]*EmailAddress, error) {
 	emails := make([]*EmailAddress, 0, 5)
-	if err := x.
+	if err := db.DefaultContext().Engine().
 		Where("uid=?", uid).
 		Asc("id").
 		Find(&emails); err != nil {
@@ -66,7 +71,7 @@ func GetEmailAddresses(uid int64) ([]*EmailAddress, error) {
 func GetEmailAddressByID(uid, id int64) (*EmailAddress, error) {
 	// User ID is required for security reasons
 	email := &EmailAddress{UID: uid}
-	if has, err := x.ID(id).Get(email); err != nil {
+	if has, err := db.DefaultContext().Engine().ID(id).Get(email); err != nil {
 		return nil, err
 	} else if !has {
 		return nil, nil
@@ -75,7 +80,7 @@ func GetEmailAddressByID(uid, id int64) (*EmailAddress, error) {
 }
 
 // isEmailActive check if email is activated with a different emailID
-func isEmailActive(e Engine, email string, excludeEmailID int64) (bool, error) {
+func isEmailActive(e db.Engine, email string, excludeEmailID int64) (bool, error) {
 	if len(email) == 0 {
 		return true, nil
 	}
@@ -99,7 +104,7 @@ func isEmailActive(e Engine, email string, excludeEmailID int64) (bool, error) {
 	return false, nil
 }
 
-func isEmailUsed(e Engine, email string) (bool, error) {
+func isEmailUsed(e db.Engine, email string) (bool, error) {
 	if len(email) == 0 {
 		return true, nil
 	}
@@ -109,10 +114,10 @@ func isEmailUsed(e Engine, email string) (bool, error) {
 
 // IsEmailUsed returns true if the email has been used.
 func IsEmailUsed(email string) (bool, error) {
-	return isEmailUsed(x, email)
+	return isEmailUsed(db.DefaultContext().Engine(), email)
 }
 
-func addEmailAddress(e Engine, email *EmailAddress) error {
+func addEmailAddress(e db.Engine, email *EmailAddress) error {
 	email.Email = strings.TrimSpace(email.Email)
 	used, err := isEmailUsed(e, email.Email)
 	if err != nil {
@@ -131,7 +136,7 @@ func addEmailAddress(e Engine, email *EmailAddress) error {
 
 // AddEmailAddress adds an email address to given user.
 func AddEmailAddress(email *EmailAddress) error {
-	return addEmailAddress(x, email)
+	return addEmailAddress(db.DefaultContext().Engine(), email)
 }
 
 // AddEmailAddresses adds an email address to given user.
@@ -154,7 +159,7 @@ func AddEmailAddresses(emails []*EmailAddress) error {
 		}
 	}
 
-	if _, err := x.Insert(emails); err != nil {
+	if _, err := db.DefaultContext().Engine().Insert(emails); err != nil {
 		return fmt.Errorf("Insert: %v", err)
 	}
 
@@ -163,7 +168,7 @@ func AddEmailAddresses(emails []*EmailAddress) error {
 
 // Activate activates the email address to given user.
 func (email *EmailAddress) Activate() error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -174,7 +179,7 @@ func (email *EmailAddress) Activate() error {
 	return sess.Commit()
 }
 
-func (email *EmailAddress) updateActivation(e Engine, activate bool) error {
+func (email *EmailAddress) updateActivation(e db.Engine, activate bool) error {
 	user, err := getUserByID(e, email.UID)
 	if err != nil {
 		return err
@@ -201,12 +206,12 @@ func DeleteEmailAddress(email *EmailAddress) (err error) {
 		UID: email.UID,
 	}
 	if email.ID > 0 {
-		deleted, err = x.ID(email.ID).Delete(&address)
+		deleted, err = db.DefaultContext().Engine().ID(email.ID).Delete(&address)
 	} else {
 		if email.Email != "" && email.LowerEmail == "" {
 			email.LowerEmail = strings.ToLower(email.Email)
 		}
-		deleted, err = x.
+		deleted, err = db.DefaultContext().Engine().
 			Where("lower_email=?", email.LowerEmail).
 			Delete(&address)
 	}
@@ -232,7 +237,7 @@ func DeleteEmailAddresses(emails []*EmailAddress) (err error) {
 
 // MakeEmailPrimary sets primary email address of given user.
 func MakeEmailPrimary(email *EmailAddress) error {
-	has, err := x.Get(email)
+	has, err := db.DefaultContext().Engine().Get(email)
 	if err != nil {
 		return err
 	} else if !has {
@@ -244,14 +249,14 @@ func MakeEmailPrimary(email *EmailAddress) error {
 	}
 
 	user := &User{}
-	has, err = x.ID(email.UID).Get(user)
+	has, err = db.DefaultContext().Engine().ID(email.UID).Get(user)
 	if err != nil {
 		return err
 	} else if !has {
 		return ErrUserNotExist{email.UID, "", 0}
 	}
 
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -341,7 +346,7 @@ func SearchEmails(opts *SearchEmailOptions) ([]*SearchEmailResult, int64, error)
 		cond = cond.And(builder.Eq{"email_address.is_activated": false})
 	}
 
-	count, err := x.Join("INNER", "`user`", "`user`.ID = email_address.uid").
+	count, err := db.DefaultContext().Engine().Join("INNER", "`user`", "`user`.ID = email_address.uid").
 		Where(cond).Count(new(EmailAddress))
 	if err != nil {
 		return nil, 0, fmt.Errorf("Count: %v", err)
@@ -355,7 +360,7 @@ func SearchEmails(opts *SearchEmailOptions) ([]*SearchEmailResult, int64, error)
 	opts.setDefaultValues()
 
 	emails := make([]*SearchEmailResult, 0, opts.PageSize)
-	err = x.Table("email_address").
+	err = db.DefaultContext().Engine().Table("email_address").
 		Select("email_address.*, `user`.name, `user`.full_name").
 		Join("INNER", "`user`", "`user`.ID = email_address.uid").
 		Where(cond).
@@ -369,7 +374,7 @@ func SearchEmails(opts *SearchEmailOptions) ([]*SearchEmailResult, int64, error)
 // ActivateUserEmail will change the activated state of an email address,
 // either primary or secondary (all in the email_address table)
 func ActivateUserEmail(userID int64, email string, activate bool) (err error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
diff --git a/models/user_mail_test.go b/models/user_mail_test.go
index 829a38c18..22e5f786b 100644
--- a/models/user_mail_test.go
+++ b/models/user_mail_test.go
@@ -7,13 +7,14 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/util"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestGetEmailAddresses(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	emails, _ := GetEmailAddresses(int64(1))
 	if assert.Len(t, emails, 3) {
@@ -30,7 +31,7 @@ func TestGetEmailAddresses(t *testing.T) {
 }
 
 func TestIsEmailUsed(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	isExist, _ := IsEmailUsed("")
 	assert.True(t, isExist)
@@ -41,7 +42,7 @@ func TestIsEmailUsed(t *testing.T) {
 }
 
 func TestAddEmailAddress(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	assert.NoError(t, AddEmailAddress(&EmailAddress{
 		Email:       "user1234567890@example.com",
@@ -60,7 +61,7 @@ func TestAddEmailAddress(t *testing.T) {
 }
 
 func TestAddEmailAddresses(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// insert multiple email address
 	emails := make([]*EmailAddress, 2)
@@ -83,7 +84,7 @@ func TestAddEmailAddresses(t *testing.T) {
 }
 
 func TestDeleteEmailAddress(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	assert.NoError(t, DeleteEmailAddress(&EmailAddress{
 		UID:        int64(1),
@@ -108,7 +109,7 @@ func TestDeleteEmailAddress(t *testing.T) {
 }
 
 func TestDeleteEmailAddresses(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// delete multiple email address
 	emails := make([]*EmailAddress, 2)
@@ -131,7 +132,7 @@ func TestDeleteEmailAddresses(t *testing.T) {
 }
 
 func TestMakeEmailPrimary(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	email := &EmailAddress{
 		Email: "user567890@example.com",
@@ -165,7 +166,7 @@ func TestMakeEmailPrimary(t *testing.T) {
 }
 
 func TestActivate(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	email := &EmailAddress{
 		ID:    int64(1),
@@ -184,7 +185,7 @@ func TestActivate(t *testing.T) {
 }
 
 func TestListEmails(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// Must find all users and their emails
 	opts := &SearchEmailOptions{
diff --git a/models/user_openid.go b/models/user_openid.go
index 597f19d77..4844b68c2 100644
--- a/models/user_openid.go
+++ b/models/user_openid.go
@@ -7,6 +7,7 @@ package models
 import (
 	"errors"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/auth/openid"
 	"code.gitea.io/gitea/modules/log"
 )
@@ -22,10 +23,14 @@ type UserOpenID struct {
 	Show bool   `xorm:"DEFAULT false"`
 }
 
+func init() {
+	db.RegisterModel(new(UserOpenID))
+}
+
 // GetUserOpenIDs returns all openid addresses that belongs to given user.
 func GetUserOpenIDs(uid int64) ([]*UserOpenID, error) {
 	openids := make([]*UserOpenID, 0, 5)
-	if err := x.
+	if err := db.DefaultContext().Engine().
 		Where("uid=?", uid).
 		Asc("id").
 		Find(&openids); err != nil {
@@ -36,7 +41,7 @@ func GetUserOpenIDs(uid int64) ([]*UserOpenID, error) {
 }
 
 // isOpenIDUsed returns true if the openid has been used.
-func isOpenIDUsed(e Engine, uri string) (bool, error) {
+func isOpenIDUsed(e db.Engine, uri string) (bool, error) {
 	if len(uri) == 0 {
 		return true, nil
 	}
@@ -45,7 +50,7 @@ func isOpenIDUsed(e Engine, uri string) (bool, error) {
 }
 
 // NOTE: make sure openid.URI is normalized already
-func addUserOpenID(e Engine, openid *UserOpenID) error {
+func addUserOpenID(e db.Engine, openid *UserOpenID) error {
 	used, err := isOpenIDUsed(e, openid.URI)
 	if err != nil {
 		return err
@@ -59,7 +64,7 @@ func addUserOpenID(e Engine, openid *UserOpenID) error {
 
 // AddUserOpenID adds an pre-verified/normalized OpenID URI to given user.
 func AddUserOpenID(openid *UserOpenID) error {
-	return addUserOpenID(x, openid)
+	return addUserOpenID(db.DefaultContext().Engine(), openid)
 }
 
 // DeleteUserOpenID deletes an openid address of given user.
@@ -70,9 +75,9 @@ func DeleteUserOpenID(openid *UserOpenID) (err error) {
 		UID: openid.UID,
 	}
 	if openid.ID > 0 {
-		deleted, err = x.ID(openid.ID).Delete(&address)
+		deleted, err = db.DefaultContext().Engine().ID(openid.ID).Delete(&address)
 	} else {
-		deleted, err = x.
+		deleted, err = db.DefaultContext().Engine().
 			Where("openid=?", openid.URI).
 			Delete(&address)
 	}
@@ -87,7 +92,7 @@ func DeleteUserOpenID(openid *UserOpenID) (err error) {
 
 // ToggleUserOpenIDVisibility toggles visibility of an openid address of given user.
 func ToggleUserOpenIDVisibility(id int64) (err error) {
-	_, err = x.Exec("update `user_open_id` set `show` = not `show` where `id` = ?", id)
+	_, err = db.DefaultContext().Engine().Exec("update `user_open_id` set `show` = not `show` where `id` = ?", id)
 	return err
 }
 
@@ -106,7 +111,7 @@ func GetUserByOpenID(uri string) (*User, error) {
 
 	// Otherwise, check in openid table
 	oid := &UserOpenID{}
-	has, err := x.Where("uri=?", uri).Get(oid)
+	has, err := db.DefaultContext().Engine().Where("uri=?", uri).Get(oid)
 	if err != nil {
 		return nil, err
 	}
diff --git a/models/user_openid_test.go b/models/user_openid_test.go
index d04b07227..3c17b0742 100644
--- a/models/user_openid_test.go
+++ b/models/user_openid_test.go
@@ -7,11 +7,12 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestGetUserOpenIDs(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	oids, err := GetUserOpenIDs(int64(1))
 	if assert.NoError(t, err) && assert.Len(t, oids, 2) {
@@ -29,7 +30,7 @@ func TestGetUserOpenIDs(t *testing.T) {
 }
 
 func TestGetUserByOpenID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	_, err := GetUserByOpenID("https://unknown")
 	if assert.Error(t, err) {
@@ -48,7 +49,7 @@ func TestGetUserByOpenID(t *testing.T) {
 }
 
 func TestToggleUserOpenIDVisibility(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	oids, err := GetUserOpenIDs(int64(2))
 	if !assert.NoError(t, err) || !assert.Len(t, oids, 1) {
 		return
diff --git a/models/user_redirect.go b/models/user_redirect.go
index 1da8b4408..4380eb598 100644
--- a/models/user_redirect.go
+++ b/models/user_redirect.go
@@ -4,7 +4,11 @@
 
 package models
 
-import "strings"
+import (
+	"strings"
+
+	"code.gitea.io/gitea/models/db"
+)
 
 // UserRedirect represents that a user name should be redirected to another
 type UserRedirect struct {
@@ -13,11 +17,15 @@ type UserRedirect struct {
 	RedirectUserID int64  // userID to redirect to
 }
 
+func init() {
+	db.RegisterModel(new(UserRedirect))
+}
+
 // LookupUserRedirect look up userID if a user has a redirect name
 func LookupUserRedirect(userName string) (int64, error) {
 	userName = strings.ToLower(userName)
 	redirect := &UserRedirect{LowerName: userName}
-	if has, err := x.Get(redirect); err != nil {
+	if has, err := db.DefaultContext().Engine().Get(redirect); err != nil {
 		return 0, err
 	} else if !has {
 		return 0, ErrUserRedirectNotExist{Name: userName}
@@ -26,7 +34,7 @@ func LookupUserRedirect(userName string) (int64, error) {
 }
 
 // newUserRedirect create a new user redirect
-func newUserRedirect(e Engine, ID int64, oldUserName, newUserName string) error {
+func newUserRedirect(e db.Engine, ID int64, oldUserName, newUserName string) error {
 	oldUserName = strings.ToLower(oldUserName)
 	newUserName = strings.ToLower(newUserName)
 
@@ -45,7 +53,7 @@ func newUserRedirect(e Engine, ID int64, oldUserName, newUserName string) error
 
 // deleteUserRedirect delete any redirect from the specified user name to
 // anything else
-func deleteUserRedirect(e Engine, userName string) error {
+func deleteUserRedirect(e db.Engine, userName string) error {
 	userName = strings.ToLower(userName)
 	_, err := e.Delete(&UserRedirect{LowerName: userName})
 	return err
diff --git a/models/user_redirect_test.go b/models/user_redirect_test.go
index 791c920bc..190778cfb 100644
--- a/models/user_redirect_test.go
+++ b/models/user_redirect_test.go
@@ -7,11 +7,12 @@ package models
 import (
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestLookupUserRedirect(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	userID, err := LookupUserRedirect("olduser1")
 	assert.NoError(t, err)
@@ -23,16 +24,16 @@ func TestLookupUserRedirect(t *testing.T) {
 
 func TestNewUserRedirect(t *testing.T) {
 	// redirect to a completely new name
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
-	assert.NoError(t, newUserRedirect(x, user.ID, user.Name, "newusername"))
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	assert.NoError(t, newUserRedirect(db.DefaultContext().Engine(), user.ID, user.Name, "newusername"))
 
-	AssertExistsAndLoadBean(t, &UserRedirect{
+	db.AssertExistsAndLoadBean(t, &UserRedirect{
 		LowerName:      user.LowerName,
 		RedirectUserID: user.ID,
 	})
-	AssertExistsAndLoadBean(t, &UserRedirect{
+	db.AssertExistsAndLoadBean(t, &UserRedirect{
 		LowerName:      "olduser1",
 		RedirectUserID: user.ID,
 	})
@@ -40,16 +41,16 @@ func TestNewUserRedirect(t *testing.T) {
 
 func TestNewUserRedirect2(t *testing.T) {
 	// redirect to previously used name
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
-	assert.NoError(t, newUserRedirect(x, user.ID, user.Name, "olduser1"))
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	assert.NoError(t, newUserRedirect(db.DefaultContext().Engine(), user.ID, user.Name, "olduser1"))
 
-	AssertExistsAndLoadBean(t, &UserRedirect{
+	db.AssertExistsAndLoadBean(t, &UserRedirect{
 		LowerName:      user.LowerName,
 		RedirectUserID: user.ID,
 	})
-	AssertNotExistsBean(t, &UserRedirect{
+	db.AssertNotExistsBean(t, &UserRedirect{
 		LowerName:      "olduser1",
 		RedirectUserID: user.ID,
 	})
@@ -57,12 +58,12 @@ func TestNewUserRedirect2(t *testing.T) {
 
 func TestNewUserRedirect3(t *testing.T) {
 	// redirect for a previously-unredirected user
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
-	assert.NoError(t, newUserRedirect(x, user.ID, user.Name, "newusername"))
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	assert.NoError(t, newUserRedirect(db.DefaultContext().Engine(), user.ID, user.Name, "newusername"))
 
-	AssertExistsAndLoadBean(t, &UserRedirect{
+	db.AssertExistsAndLoadBean(t, &UserRedirect{
 		LowerName:      user.LowerName,
 		RedirectUserID: user.ID,
 	})
diff --git a/models/user_test.go b/models/user_test.go
index a76bca0ed..aadf7e4c5 100644
--- a/models/user_test.go
+++ b/models/user_test.go
@@ -10,6 +10,7 @@ import (
 	"strings"
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/util"
@@ -18,7 +19,7 @@ import (
 )
 
 func TestUserIsPublicMember(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	tt := []struct {
 		uid      int64
@@ -44,7 +45,7 @@ func testUserIsPublicMember(t *testing.T, uid, orgID int64, expected bool) {
 }
 
 func TestIsUserOrgOwner(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	tt := []struct {
 		uid      int64
@@ -70,7 +71,7 @@ func testIsUserOrgOwner(t *testing.T, uid, orgID int64, expected bool) {
 }
 
 func TestGetUserEmailsByNames(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// ignore none active user email
 	assert.Equal(t, []string{"user8@example.com"}, GetUserEmailsByNames([]string{"user8", "user9"}))
@@ -80,12 +81,12 @@ func TestGetUserEmailsByNames(t *testing.T) {
 }
 
 func TestCanCreateOrganization(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	admin := AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
+	admin := db.AssertExistsAndLoadBean(t, &User{ID: 1}).(*User)
 	assert.True(t, admin.CanCreateOrganization())
 
-	user := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	assert.True(t, user.CanCreateOrganization())
 	// Disable user create organization permission.
 	user.AllowCreateOrganization = false
@@ -98,7 +99,7 @@ func TestCanCreateOrganization(t *testing.T) {
 }
 
 func TestSearchUsers(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	testSuccess := func(opts *SearchUserOptions, expectedUserOrOrgIDs []int64) {
 		users, _, err := SearchUsers(opts)
 		assert.NoError(t, err)
@@ -155,11 +156,11 @@ func TestSearchUsers(t *testing.T) {
 
 func TestDeleteUser(t *testing.T) {
 	test := func(userID int64) {
-		assert.NoError(t, PrepareTestDatabase())
-		user := AssertExistsAndLoadBean(t, &User{ID: userID}).(*User)
+		assert.NoError(t, db.PrepareTestDatabase())
+		user := db.AssertExistsAndLoadBean(t, &User{ID: userID}).(*User)
 
 		ownedRepos := make([]*Repository, 0, 10)
-		assert.NoError(t, x.Find(&ownedRepos, &Repository{OwnerID: userID}))
+		assert.NoError(t, db.DefaultContext().Engine().Find(&ownedRepos, &Repository{OwnerID: userID}))
 		if len(ownedRepos) > 0 {
 			err := DeleteUser(user)
 			assert.Error(t, err)
@@ -168,7 +169,7 @@ func TestDeleteUser(t *testing.T) {
 		}
 
 		orgUsers := make([]*OrgUser, 0, 10)
-		assert.NoError(t, x.Find(&orgUsers, &OrgUser{UID: userID}))
+		assert.NoError(t, db.DefaultContext().Engine().Find(&orgUsers, &OrgUser{UID: userID}))
 		for _, orgUser := range orgUsers {
 			if err := RemoveOrgUser(orgUser.OrgID, orgUser.UID); err != nil {
 				assert.True(t, IsErrLastOrgOwner(err))
@@ -176,7 +177,7 @@ func TestDeleteUser(t *testing.T) {
 			}
 		}
 		assert.NoError(t, DeleteUser(user))
-		AssertNotExistsBean(t, &User{ID: userID})
+		db.AssertNotExistsBean(t, &User{ID: userID})
 		CheckConsistencyFor(t, &User{}, &Repository{})
 	}
 	test(2)
@@ -184,12 +185,12 @@ func TestDeleteUser(t *testing.T) {
 	test(8)
 	test(11)
 
-	org := AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
+	org := db.AssertExistsAndLoadBean(t, &User{ID: 3}).(*User)
 	assert.Error(t, DeleteUser(org))
 }
 
 func TestEmailNotificationPreferences(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	for _, test := range []struct {
 		expected string
@@ -205,7 +206,7 @@ func TestEmailNotificationPreferences(t *testing.T) {
 		{EmailNotificationsEnabled, 8},
 		{EmailNotificationsOnMention, 9},
 	} {
-		user := AssertExistsAndLoadBean(t, &User{ID: test.userID}).(*User)
+		user := db.AssertExistsAndLoadBean(t, &User{ID: test.userID}).(*User)
 		assert.Equal(t, test.expected, user.EmailNotifications())
 
 		// Try all possible settings
@@ -257,10 +258,10 @@ func BenchmarkHashPassword(b *testing.B) {
 }
 
 func TestGetOrgRepositoryIDs(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	user2 := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
-	user4 := AssertExistsAndLoadBean(t, &User{ID: 4}).(*User)
-	user5 := AssertExistsAndLoadBean(t, &User{ID: 5}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	user2 := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user4 := db.AssertExistsAndLoadBean(t, &User{ID: 4}).(*User)
+	user5 := db.AssertExistsAndLoadBean(t, &User{ID: 5}).(*User)
 
 	accessibleRepos, err := user2.GetOrgRepositoryIDs()
 	assert.NoError(t, err)
@@ -280,7 +281,7 @@ func TestGetOrgRepositoryIDs(t *testing.T) {
 
 func TestNewGitSig(t *testing.T) {
 	users := make([]*User, 0, 20)
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	sess.Find(&users)
 
@@ -295,7 +296,7 @@ func TestNewGitSig(t *testing.T) {
 
 func TestDisplayName(t *testing.T) {
 	users := make([]*User, 0, 20)
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	sess.Find(&users)
 
@@ -370,7 +371,7 @@ func TestCreateUser_Issue5882(t *testing.T) {
 }
 
 func TestGetUserIDsByNames(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// ignore non existing
 	IDs, err := GetUserIDsByNames([]string{"user1", "user2", "none_existing_user"}, true)
@@ -384,7 +385,7 @@ func TestGetUserIDsByNames(t *testing.T) {
 }
 
 func TestGetMaileableUsersByIDs(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	results, err := GetMaileableUsersByIDs([]int64{1, 4}, false)
 	assert.NoError(t, err)
@@ -403,9 +404,9 @@ func TestGetMaileableUsersByIDs(t *testing.T) {
 }
 
 func TestAddLdapSSHPublicKeys(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	s := &LoginSource{ID: 1}
 
 	testCases := []struct {
@@ -471,19 +472,19 @@ ssh-dss AAAAB3NzaC1kc3MAAACBAOChCC7lf6Uo9n7BmZ6M8St19PZf4Tn59NriyboW2x/DZuYAz3ib
 }
 
 func TestUpdateUser(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	user := AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	user := db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 
 	user.KeepActivityPrivate = true
 	assert.NoError(t, UpdateUser(user))
-	user = AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user = db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	assert.True(t, user.KeepActivityPrivate)
 
 	setting.Service.AllowedUserVisibilityModesSlice = []bool{true, false, false}
 	user.KeepActivityPrivate = false
 	user.Visibility = structs.VisibleTypePrivate
 	assert.Error(t, UpdateUser(user))
-	user = AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
+	user = db.AssertExistsAndLoadBean(t, &User{ID: 2}).(*User)
 	assert.True(t, user.KeepActivityPrivate)
 
 	user.Email = "no mail@mail.org"
diff --git a/models/userlist.go b/models/userlist.go
index 53e380cd7..9741c90cc 100644
--- a/models/userlist.go
+++ b/models/userlist.go
@@ -7,6 +7,7 @@ package models
 import (
 	"fmt"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 )
 
@@ -28,7 +29,7 @@ func (users UserList) IsUserOrgOwner(orgID int64) map[int64]bool {
 	for _, user := range users {
 		results[user.ID] = false // Set default to false
 	}
-	ownerMaps, err := users.loadOrganizationOwners(x, orgID)
+	ownerMaps, err := users.loadOrganizationOwners(db.DefaultContext().Engine(), orgID)
 	if err == nil {
 		for _, owner := range ownerMaps {
 			results[owner.UID] = true
@@ -37,7 +38,7 @@ func (users UserList) IsUserOrgOwner(orgID int64) map[int64]bool {
 	return results
 }
 
-func (users UserList) loadOrganizationOwners(e Engine, orgID int64) (map[int64]*TeamUser, error) {
+func (users UserList) loadOrganizationOwners(e db.Engine, orgID int64) (map[int64]*TeamUser, error) {
 	if len(users) == 0 {
 		return nil, nil
 	}
@@ -68,7 +69,7 @@ func (users UserList) GetTwoFaStatus() map[int64]bool {
 	for _, user := range users {
 		results[user.ID] = false // Set default to false
 	}
-	tokenMaps, err := users.loadTwoFactorStatus(x)
+	tokenMaps, err := users.loadTwoFactorStatus(db.DefaultContext().Engine())
 	if err == nil {
 		for _, token := range tokenMaps {
 			results[token.UID] = true
@@ -78,7 +79,7 @@ func (users UserList) GetTwoFaStatus() map[int64]bool {
 	return results
 }
 
-func (users UserList) loadTwoFactorStatus(e Engine) (map[int64]*TwoFactor, error) {
+func (users UserList) loadTwoFactorStatus(e db.Engine) (map[int64]*TwoFactor, error) {
 	if len(users) == 0 {
 		return nil, nil
 	}
diff --git a/models/userlist_test.go b/models/userlist_test.go
index 5c1af6c20..9e75f783f 100644
--- a/models/userlist_test.go
+++ b/models/userlist_test.go
@@ -8,11 +8,12 @@ import (
 	"fmt"
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestUserListIsPublicMember(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	tt := []struct {
 		orgid    int64
 		expected map[int64]bool
@@ -38,7 +39,7 @@ func testUserListIsPublicMember(t *testing.T, orgID int64, expected map[int64]bo
 }
 
 func TestUserListIsUserOrgOwner(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	tt := []struct {
 		orgid    int64
 		expected map[int64]bool
@@ -64,7 +65,7 @@ func testUserListIsUserOrgOwner(t *testing.T, orgID int64, expected map[int64]bo
 }
 
 func TestUserListIsTwoFaEnrolled(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	tt := []struct {
 		orgid    int64
 		expected map[int64]bool
diff --git a/models/webhook.go b/models/webhook.go
index e19d0203c..fca6eec67 100644
--- a/models/webhook.go
+++ b/models/webhook.go
@@ -11,6 +11,7 @@ import (
 	"strings"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/json"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -159,6 +160,11 @@ type Webhook struct {
 	UpdatedUnix timeutil.TimeStamp `xorm:"INDEX updated"`
 }
 
+func init() {
+	db.RegisterModel(new(Webhook))
+	db.RegisterModel(new(HookTask))
+}
+
 // AfterLoad updates the webhook object upon setting a column
 func (w *Webhook) AfterLoad() {
 	w.HookEvent = &HookEvent{}
@@ -345,10 +351,10 @@ func (w *Webhook) EventsArray() []string {
 
 // CreateWebhook creates a new web hook.
 func CreateWebhook(w *Webhook) error {
-	return createWebhook(x, w)
+	return createWebhook(db.DefaultContext().Engine(), w)
 }
 
-func createWebhook(e Engine, w *Webhook) error {
+func createWebhook(e db.Engine, w *Webhook) error {
 	w.Type = strings.TrimSpace(w.Type)
 	_, err := e.Insert(w)
 	return err
@@ -357,7 +363,7 @@ func createWebhook(e Engine, w *Webhook) error {
 // getWebhook uses argument bean as query condition,
 // ID must be specified and do not assign unnecessary fields.
 func getWebhook(bean *Webhook) (*Webhook, error) {
-	has, err := x.Get(bean)
+	has, err := db.DefaultContext().Engine().Get(bean)
 	if err != nil {
 		return nil, err
 	} else if !has {
@@ -411,7 +417,7 @@ func (opts *ListWebhookOptions) toCond() builder.Cond {
 	return cond
 }
 
-func listWebhooksByOpts(e Engine, opts *ListWebhookOptions) ([]*Webhook, error) {
+func listWebhooksByOpts(e db.Engine, opts *ListWebhookOptions) ([]*Webhook, error) {
 	sess := e.Where(opts.toCond())
 
 	if opts.Page != 0 {
@@ -428,20 +434,20 @@ func listWebhooksByOpts(e Engine, opts *ListWebhookOptions) ([]*Webhook, error)
 
 // ListWebhooksByOpts return webhooks based on options
 func ListWebhooksByOpts(opts *ListWebhookOptions) ([]*Webhook, error) {
-	return listWebhooksByOpts(x, opts)
+	return listWebhooksByOpts(db.DefaultContext().Engine(), opts)
 }
 
 // CountWebhooksByOpts count webhooks based on options and ignore pagination
 func CountWebhooksByOpts(opts *ListWebhookOptions) (int64, error) {
-	return x.Where(opts.toCond()).Count(&Webhook{})
+	return db.DefaultContext().Engine().Where(opts.toCond()).Count(&Webhook{})
 }
 
 // GetDefaultWebhooks returns all admin-default webhooks.
 func GetDefaultWebhooks() ([]*Webhook, error) {
-	return getDefaultWebhooks(x)
+	return getDefaultWebhooks(db.DefaultContext().Engine())
 }
 
-func getDefaultWebhooks(e Engine) ([]*Webhook, error) {
+func getDefaultWebhooks(e db.Engine) ([]*Webhook, error) {
 	webhooks := make([]*Webhook, 0, 5)
 	return webhooks, e.
 		Where("repo_id=? AND org_id=? AND is_system_webhook=?", 0, 0, false).
@@ -451,7 +457,7 @@ func getDefaultWebhooks(e Engine) ([]*Webhook, error) {
 // GetSystemOrDefaultWebhook returns admin system or default webhook by given ID.
 func GetSystemOrDefaultWebhook(id int64) (*Webhook, error) {
 	webhook := &Webhook{ID: id}
-	has, err := x.
+	has, err := db.DefaultContext().Engine().
 		Where("repo_id=? AND org_id=?", 0, 0).
 		Get(webhook)
 	if err != nil {
@@ -464,10 +470,10 @@ func GetSystemOrDefaultWebhook(id int64) (*Webhook, error) {
 
 // GetSystemWebhooks returns all admin system webhooks.
 func GetSystemWebhooks() ([]*Webhook, error) {
-	return getSystemWebhooks(x)
+	return getSystemWebhooks(db.DefaultContext().Engine())
 }
 
-func getSystemWebhooks(e Engine) ([]*Webhook, error) {
+func getSystemWebhooks(e db.Engine) ([]*Webhook, error) {
 	webhooks := make([]*Webhook, 0, 5)
 	return webhooks, e.
 		Where("repo_id=? AND org_id=? AND is_system_webhook=?", 0, 0, true).
@@ -476,20 +482,20 @@ func getSystemWebhooks(e Engine) ([]*Webhook, error) {
 
 // UpdateWebhook updates information of webhook.
 func UpdateWebhook(w *Webhook) error {
-	_, err := x.ID(w.ID).AllCols().Update(w)
+	_, err := db.DefaultContext().Engine().ID(w.ID).AllCols().Update(w)
 	return err
 }
 
 // UpdateWebhookLastStatus updates last status of webhook.
 func UpdateWebhookLastStatus(w *Webhook) error {
-	_, err := x.ID(w.ID).Cols("last_status").Update(w)
+	_, err := db.DefaultContext().Engine().ID(w.ID).Cols("last_status").Update(w)
 	return err
 }
 
 // deleteWebhook uses argument bean as query condition,
 // ID must be specified and do not assign unnecessary fields.
 func deleteWebhook(bean *Webhook) (err error) {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err = sess.Begin(); err != nil {
 		return err
@@ -524,7 +530,7 @@ func DeleteWebhookByOrgID(orgID, id int64) error {
 
 // DeleteDefaultSystemWebhook deletes an admin-configured default or system webhook (where Org and Repo ID both 0)
 func DeleteDefaultSystemWebhook(id int64) error {
-	sess := x.NewSession()
+	sess := db.DefaultContext().NewSession()
 	defer sess.Close()
 	if err := sess.Begin(); err != nil {
 		return err
@@ -547,7 +553,7 @@ func DeleteDefaultSystemWebhook(id int64) error {
 }
 
 // copyDefaultWebhooksToRepo creates copies of the default webhooks in a new repo
-func copyDefaultWebhooksToRepo(e Engine, repoID int64) error {
+func copyDefaultWebhooksToRepo(e db.Engine, repoID int64) error {
 	ws, err := getDefaultWebhooks(e)
 	if err != nil {
 		return fmt.Errorf("GetDefaultWebhooks: %v", err)
@@ -707,7 +713,7 @@ func (t *HookTask) simpleMarshalJSON(v interface{}) string {
 // HookTasks returns a list of hook tasks by given conditions.
 func HookTasks(hookID int64, page int) ([]*HookTask, error) {
 	tasks := make([]*HookTask, 0, setting.Webhook.PagingNum)
-	return tasks, x.
+	return tasks, db.DefaultContext().Engine().
 		Limit(setting.Webhook.PagingNum, (page-1)*setting.Webhook.PagingNum).
 		Where("hook_id=?", hookID).
 		Desc("id").
@@ -717,10 +723,10 @@ func HookTasks(hookID int64, page int) ([]*HookTask, error) {
 // CreateHookTask creates a new hook task,
 // it handles conversion from Payload to PayloadContent.
 func CreateHookTask(t *HookTask) error {
-	return createHookTask(x, t)
+	return createHookTask(db.DefaultContext().Engine(), t)
 }
 
-func createHookTask(e Engine, t *HookTask) error {
+func createHookTask(e db.Engine, t *HookTask) error {
 	data, err := t.Payloader.JSONPayload()
 	if err != nil {
 		return err
@@ -733,14 +739,14 @@ func createHookTask(e Engine, t *HookTask) error {
 
 // UpdateHookTask updates information of hook task.
 func UpdateHookTask(t *HookTask) error {
-	_, err := x.ID(t.ID).AllCols().Update(t)
+	_, err := db.DefaultContext().Engine().ID(t.ID).AllCols().Update(t)
 	return err
 }
 
 // FindUndeliveredHookTasks represents find the undelivered hook tasks
 func FindUndeliveredHookTasks() ([]*HookTask, error) {
 	tasks := make([]*HookTask, 0, 10)
-	if err := x.Where("is_delivered=?", false).Find(&tasks); err != nil {
+	if err := db.DefaultContext().Engine().Where("is_delivered=?", false).Find(&tasks); err != nil {
 		return nil, err
 	}
 	return tasks, nil
@@ -749,7 +755,7 @@ func FindUndeliveredHookTasks() ([]*HookTask, error) {
 // FindRepoUndeliveredHookTasks represents find the undelivered hook tasks of one repository
 func FindRepoUndeliveredHookTasks(repoID int64) ([]*HookTask, error) {
 	tasks := make([]*HookTask, 0, 5)
-	if err := x.Where("repo_id=? AND is_delivered=?", repoID, false).Find(&tasks); err != nil {
+	if err := db.DefaultContext().Engine().Where("repo_id=? AND is_delivered=?", repoID, false).Find(&tasks); err != nil {
 		return nil, err
 	}
 	return tasks, nil
@@ -761,7 +767,7 @@ func CleanupHookTaskTable(ctx context.Context, cleanupType HookTaskCleanupType,
 
 	if cleanupType == OlderThan {
 		deleteOlderThan := time.Now().Add(-olderThan).UnixNano()
-		deletes, err := x.
+		deletes, err := db.DefaultContext().Engine().
 			Where("is_delivered = ? and delivered < ?", true, deleteOlderThan).
 			Delete(new(HookTask))
 		if err != nil {
@@ -770,7 +776,7 @@ func CleanupHookTaskTable(ctx context.Context, cleanupType HookTaskCleanupType,
 		log.Trace("Deleted %d rows from hook_task", deletes)
 	} else if cleanupType == PerWebhook {
 		hookIDs := make([]int64, 0, 10)
-		err := x.Table("webhook").
+		err := db.DefaultContext().Engine().Table("webhook").
 			Where("id > 0").
 			Cols("id").
 			Find(&hookIDs)
@@ -795,7 +801,7 @@ func CleanupHookTaskTable(ctx context.Context, cleanupType HookTaskCleanupType,
 func deleteDeliveredHookTasksByWebhook(hookID int64, numberDeliveriesToKeep int) error {
 	log.Trace("Deleting hook_task rows for webhook %d, keeping the most recent %d deliveries", hookID, numberDeliveriesToKeep)
 	deliveryDates := make([]int64, 0, 10)
-	err := x.Table("hook_task").
+	err := db.DefaultContext().Engine().Table("hook_task").
 		Where("hook_task.hook_id = ? AND hook_task.is_delivered = ? AND hook_task.delivered is not null", hookID, true).
 		Cols("hook_task.delivered").
 		Join("INNER", "webhook", "hook_task.hook_id = webhook.id").
@@ -807,7 +813,7 @@ func deleteDeliveredHookTasksByWebhook(hookID int64, numberDeliveriesToKeep int)
 	}
 
 	if len(deliveryDates) > 0 {
-		deletes, err := x.
+		deletes, err := db.DefaultContext().Engine().
 			Where("hook_id = ? and is_delivered = ? and delivered <= ?", hookID, true, deliveryDates[0]).
 			Delete(new(HookTask))
 		if err != nil {
diff --git a/models/webhook_test.go b/models/webhook_test.go
index 625d64385..d48fa365b 100644
--- a/models/webhook_test.go
+++ b/models/webhook_test.go
@@ -9,6 +9,7 @@ import (
 	"testing"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/json"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/util"
@@ -28,23 +29,23 @@ func TestIsValidHookContentType(t *testing.T) {
 }
 
 func TestWebhook_History(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	webhook := AssertExistsAndLoadBean(t, &Webhook{ID: 1}).(*Webhook)
+	assert.NoError(t, db.PrepareTestDatabase())
+	webhook := db.AssertExistsAndLoadBean(t, &Webhook{ID: 1}).(*Webhook)
 	tasks, err := webhook.History(0)
 	assert.NoError(t, err)
 	if assert.Len(t, tasks, 1) {
 		assert.Equal(t, int64(1), tasks[0].ID)
 	}
 
-	webhook = AssertExistsAndLoadBean(t, &Webhook{ID: 2}).(*Webhook)
+	webhook = db.AssertExistsAndLoadBean(t, &Webhook{ID: 2}).(*Webhook)
 	tasks, err = webhook.History(0)
 	assert.NoError(t, err)
 	assert.Len(t, tasks, 0)
 }
 
 func TestWebhook_UpdateEvent(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	webhook := AssertExistsAndLoadBean(t, &Webhook{ID: 1}).(*Webhook)
+	assert.NoError(t, db.PrepareTestDatabase())
+	webhook := db.AssertExistsAndLoadBean(t, &Webhook{ID: 1}).(*Webhook)
 	hookEvent := &HookEvent{
 		PushOnly:       true,
 		SendEverything: false,
@@ -90,35 +91,35 @@ func TestCreateWebhook(t *testing.T) {
 		ContentType: ContentTypeJSON,
 		Events:      `{"push_only":false,"send_everything":false,"choose_events":false,"events":{"create":false,"push":true,"pull_request":true}}`,
 	}
-	AssertNotExistsBean(t, hook)
+	db.AssertNotExistsBean(t, hook)
 	assert.NoError(t, CreateWebhook(hook))
-	AssertExistsAndLoadBean(t, hook)
+	db.AssertExistsAndLoadBean(t, hook)
 }
 
 func TestGetWebhookByRepoID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	hook, err := GetWebhookByRepoID(1, 1)
 	assert.NoError(t, err)
 	assert.Equal(t, int64(1), hook.ID)
 
-	_, err = GetWebhookByRepoID(NonexistentID, NonexistentID)
+	_, err = GetWebhookByRepoID(db.NonexistentID, db.NonexistentID)
 	assert.Error(t, err)
 	assert.True(t, IsErrWebhookNotExist(err))
 }
 
 func TestGetWebhookByOrgID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	hook, err := GetWebhookByOrgID(3, 3)
 	assert.NoError(t, err)
 	assert.Equal(t, int64(3), hook.ID)
 
-	_, err = GetWebhookByOrgID(NonexistentID, NonexistentID)
+	_, err = GetWebhookByOrgID(db.NonexistentID, db.NonexistentID)
 	assert.Error(t, err)
 	assert.True(t, IsErrWebhookNotExist(err))
 }
 
 func TestGetActiveWebhooksByRepoID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	hooks, err := ListWebhooksByOpts(&ListWebhookOptions{RepoID: 1, IsActive: util.OptionalBoolTrue})
 	assert.NoError(t, err)
 	if assert.Len(t, hooks, 1) {
@@ -128,7 +129,7 @@ func TestGetActiveWebhooksByRepoID(t *testing.T) {
 }
 
 func TestGetWebhooksByRepoID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	hooks, err := ListWebhooksByOpts(&ListWebhookOptions{RepoID: 1})
 	assert.NoError(t, err)
 	if assert.Len(t, hooks, 2) {
@@ -138,7 +139,7 @@ func TestGetWebhooksByRepoID(t *testing.T) {
 }
 
 func TestGetActiveWebhooksByOrgID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	hooks, err := ListWebhooksByOpts(&ListWebhookOptions{OrgID: 3, IsActive: util.OptionalBoolTrue})
 	assert.NoError(t, err)
 	if assert.Len(t, hooks, 1) {
@@ -148,7 +149,7 @@ func TestGetActiveWebhooksByOrgID(t *testing.T) {
 }
 
 func TestGetWebhooksByOrgID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	hooks, err := ListWebhooksByOpts(&ListWebhookOptions{OrgID: 3})
 	assert.NoError(t, err)
 	if assert.Len(t, hooks, 1) {
@@ -158,76 +159,76 @@ func TestGetWebhooksByOrgID(t *testing.T) {
 }
 
 func TestUpdateWebhook(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	hook := AssertExistsAndLoadBean(t, &Webhook{ID: 2}).(*Webhook)
+	assert.NoError(t, db.PrepareTestDatabase())
+	hook := db.AssertExistsAndLoadBean(t, &Webhook{ID: 2}).(*Webhook)
 	hook.IsActive = true
 	hook.ContentType = ContentTypeForm
-	AssertNotExistsBean(t, hook)
+	db.AssertNotExistsBean(t, hook)
 	assert.NoError(t, UpdateWebhook(hook))
-	AssertExistsAndLoadBean(t, hook)
+	db.AssertExistsAndLoadBean(t, hook)
 }
 
 func TestDeleteWebhookByRepoID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	AssertExistsAndLoadBean(t, &Webhook{ID: 2, RepoID: 1})
+	assert.NoError(t, db.PrepareTestDatabase())
+	db.AssertExistsAndLoadBean(t, &Webhook{ID: 2, RepoID: 1})
 	assert.NoError(t, DeleteWebhookByRepoID(1, 2))
-	AssertNotExistsBean(t, &Webhook{ID: 2, RepoID: 1})
+	db.AssertNotExistsBean(t, &Webhook{ID: 2, RepoID: 1})
 
-	err := DeleteWebhookByRepoID(NonexistentID, NonexistentID)
+	err := DeleteWebhookByRepoID(db.NonexistentID, db.NonexistentID)
 	assert.Error(t, err)
 	assert.True(t, IsErrWebhookNotExist(err))
 }
 
 func TestDeleteWebhookByOrgID(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	AssertExistsAndLoadBean(t, &Webhook{ID: 3, OrgID: 3})
+	assert.NoError(t, db.PrepareTestDatabase())
+	db.AssertExistsAndLoadBean(t, &Webhook{ID: 3, OrgID: 3})
 	assert.NoError(t, DeleteWebhookByOrgID(3, 3))
-	AssertNotExistsBean(t, &Webhook{ID: 3, OrgID: 3})
+	db.AssertNotExistsBean(t, &Webhook{ID: 3, OrgID: 3})
 
-	err := DeleteWebhookByOrgID(NonexistentID, NonexistentID)
+	err := DeleteWebhookByOrgID(db.NonexistentID, db.NonexistentID)
 	assert.Error(t, err)
 	assert.True(t, IsErrWebhookNotExist(err))
 }
 
 func TestHookTasks(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	hookTasks, err := HookTasks(1, 1)
 	assert.NoError(t, err)
 	if assert.Len(t, hookTasks, 1) {
 		assert.Equal(t, int64(1), hookTasks[0].ID)
 	}
 
-	hookTasks, err = HookTasks(NonexistentID, 1)
+	hookTasks, err = HookTasks(db.NonexistentID, 1)
 	assert.NoError(t, err)
 	assert.Len(t, hookTasks, 0)
 }
 
 func TestCreateHookTask(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	hookTask := &HookTask{
 		RepoID:    3,
 		HookID:    3,
 		Payloader: &api.PushPayload{},
 	}
-	AssertNotExistsBean(t, hookTask)
+	db.AssertNotExistsBean(t, hookTask)
 	assert.NoError(t, CreateHookTask(hookTask))
-	AssertExistsAndLoadBean(t, hookTask)
+	db.AssertExistsAndLoadBean(t, hookTask)
 }
 
 func TestUpdateHookTask(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	hook := AssertExistsAndLoadBean(t, &HookTask{ID: 1}).(*HookTask)
+	hook := db.AssertExistsAndLoadBean(t, &HookTask{ID: 1}).(*HookTask)
 	hook.PayloadContent = "new payload content"
 	hook.DeliveredString = "new delivered string"
 	hook.IsDelivered = true
-	AssertNotExistsBean(t, hook)
+	db.AssertNotExistsBean(t, hook)
 	assert.NoError(t, UpdateHookTask(hook))
-	AssertExistsAndLoadBean(t, hook)
+	db.AssertExistsAndLoadBean(t, hook)
 }
 
 func TestCleanupHookTaskTable_PerWebhook_DeletesDelivered(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	hookTask := &HookTask{
 		RepoID:      3,
 		HookID:      3,
@@ -235,32 +236,32 @@ func TestCleanupHookTaskTable_PerWebhook_DeletesDelivered(t *testing.T) {
 		IsDelivered: true,
 		Delivered:   time.Now().UnixNano(),
 	}
-	AssertNotExistsBean(t, hookTask)
+	db.AssertNotExistsBean(t, hookTask)
 	assert.NoError(t, CreateHookTask(hookTask))
-	AssertExistsAndLoadBean(t, hookTask)
+	db.AssertExistsAndLoadBean(t, hookTask)
 
 	assert.NoError(t, CleanupHookTaskTable(context.Background(), PerWebhook, 168*time.Hour, 0))
-	AssertNotExistsBean(t, hookTask)
+	db.AssertNotExistsBean(t, hookTask)
 }
 
 func TestCleanupHookTaskTable_PerWebhook_LeavesUndelivered(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	hookTask := &HookTask{
 		RepoID:      2,
 		HookID:      4,
 		Payloader:   &api.PushPayload{},
 		IsDelivered: false,
 	}
-	AssertNotExistsBean(t, hookTask)
+	db.AssertNotExistsBean(t, hookTask)
 	assert.NoError(t, CreateHookTask(hookTask))
-	AssertExistsAndLoadBean(t, hookTask)
+	db.AssertExistsAndLoadBean(t, hookTask)
 
 	assert.NoError(t, CleanupHookTaskTable(context.Background(), PerWebhook, 168*time.Hour, 0))
-	AssertExistsAndLoadBean(t, hookTask)
+	db.AssertExistsAndLoadBean(t, hookTask)
 }
 
 func TestCleanupHookTaskTable_PerWebhook_LeavesMostRecentTask(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	hookTask := &HookTask{
 		RepoID:      2,
 		HookID:      4,
@@ -268,16 +269,16 @@ func TestCleanupHookTaskTable_PerWebhook_LeavesMostRecentTask(t *testing.T) {
 		IsDelivered: true,
 		Delivered:   time.Now().UnixNano(),
 	}
-	AssertNotExistsBean(t, hookTask)
+	db.AssertNotExistsBean(t, hookTask)
 	assert.NoError(t, CreateHookTask(hookTask))
-	AssertExistsAndLoadBean(t, hookTask)
+	db.AssertExistsAndLoadBean(t, hookTask)
 
 	assert.NoError(t, CleanupHookTaskTable(context.Background(), PerWebhook, 168*time.Hour, 1))
-	AssertExistsAndLoadBean(t, hookTask)
+	db.AssertExistsAndLoadBean(t, hookTask)
 }
 
 func TestCleanupHookTaskTable_OlderThan_DeletesDelivered(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	hookTask := &HookTask{
 		RepoID:      3,
 		HookID:      3,
@@ -285,32 +286,32 @@ func TestCleanupHookTaskTable_OlderThan_DeletesDelivered(t *testing.T) {
 		IsDelivered: true,
 		Delivered:   time.Now().AddDate(0, 0, -8).UnixNano(),
 	}
-	AssertNotExistsBean(t, hookTask)
+	db.AssertNotExistsBean(t, hookTask)
 	assert.NoError(t, CreateHookTask(hookTask))
-	AssertExistsAndLoadBean(t, hookTask)
+	db.AssertExistsAndLoadBean(t, hookTask)
 
 	assert.NoError(t, CleanupHookTaskTable(context.Background(), OlderThan, 168*time.Hour, 0))
-	AssertNotExistsBean(t, hookTask)
+	db.AssertNotExistsBean(t, hookTask)
 }
 
 func TestCleanupHookTaskTable_OlderThan_LeavesUndelivered(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	hookTask := &HookTask{
 		RepoID:      2,
 		HookID:      4,
 		Payloader:   &api.PushPayload{},
 		IsDelivered: false,
 	}
-	AssertNotExistsBean(t, hookTask)
+	db.AssertNotExistsBean(t, hookTask)
 	assert.NoError(t, CreateHookTask(hookTask))
-	AssertExistsAndLoadBean(t, hookTask)
+	db.AssertExistsAndLoadBean(t, hookTask)
 
 	assert.NoError(t, CleanupHookTaskTable(context.Background(), OlderThan, 168*time.Hour, 0))
-	AssertExistsAndLoadBean(t, hookTask)
+	db.AssertExistsAndLoadBean(t, hookTask)
 }
 
 func TestCleanupHookTaskTable_OlderThan_LeavesTaskEarlierThanAgeToDelete(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	hookTask := &HookTask{
 		RepoID:      2,
 		HookID:      4,
@@ -318,10 +319,10 @@ func TestCleanupHookTaskTable_OlderThan_LeavesTaskEarlierThanAgeToDelete(t *test
 		IsDelivered: true,
 		Delivered:   time.Now().AddDate(0, 0, -6).UnixNano(),
 	}
-	AssertNotExistsBean(t, hookTask)
+	db.AssertNotExistsBean(t, hookTask)
 	assert.NoError(t, CreateHookTask(hookTask))
-	AssertExistsAndLoadBean(t, hookTask)
+	db.AssertExistsAndLoadBean(t, hookTask)
 
 	assert.NoError(t, CleanupHookTaskTable(context.Background(), OlderThan, 168*time.Hour, 0))
-	AssertExistsAndLoadBean(t, hookTask)
+	db.AssertExistsAndLoadBean(t, hookTask)
 }
diff --git a/models/wiki_test.go b/models/wiki_test.go
index 244c4f255..f1435e817 100644
--- a/models/wiki_test.go
+++ b/models/wiki_test.go
@@ -8,37 +8,38 @@ import (
 	"path/filepath"
 	"testing"
 
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestRepository_WikiCloneLink(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
 	cloneLink := repo.WikiCloneLink()
 	assert.Equal(t, "ssh://runuser@try.gitea.io:3000/user2/repo1.wiki.git", cloneLink.SSH)
 	assert.Equal(t, "https://try.gitea.io/user2/repo1.wiki.git", cloneLink.HTTPS)
 }
 
 func TestWikiPath(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	expected := filepath.Join(setting.RepoRootPath, "user2/repo1.wiki.git")
 	assert.Equal(t, expected, WikiPath("user2", "repo1"))
 }
 
 func TestRepository_WikiPath(t *testing.T) {
-	assert.NoError(t, PrepareTestDatabase())
-	repo := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	assert.NoError(t, db.PrepareTestDatabase())
+	repo := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
 	expected := filepath.Join(setting.RepoRootPath, "user2/repo1.wiki.git")
 	assert.Equal(t, expected, repo.WikiPath())
 }
 
 func TestRepository_HasWiki(t *testing.T) {
-	PrepareTestEnv(t)
-	repo1 := AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
+	db.PrepareTestEnv(t)
+	repo1 := db.AssertExistsAndLoadBean(t, &Repository{ID: 1}).(*Repository)
 	assert.True(t, repo1.HasWiki())
-	repo2 := AssertExistsAndLoadBean(t, &Repository{ID: 2}).(*Repository)
+	repo2 := db.AssertExistsAndLoadBean(t, &Repository{ID: 2}).(*Repository)
 	assert.False(t, repo2.HasWiki())
 }
diff --git a/modules/convert/git_commit_test.go b/modules/convert/git_commit_test.go
index aa3557170..298a006cb 100644
--- a/modules/convert/git_commit_test.go
+++ b/modules/convert/git_commit_test.go
@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/util"
@@ -17,8 +18,8 @@ import (
 )
 
 func TestToCommitMeta(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
-	headRepo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	assert.NoError(t, db.PrepareTestDatabase())
+	headRepo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 	sha1, _ := git.NewIDFromString("0000000000000000000000000000000000000000")
 	signature := &git.Signature{Name: "Test Signature", Email: "test@email.com", When: time.Unix(0, 0)}
 	tag := &git.Tag{
diff --git a/modules/convert/issue_test.go b/modules/convert/issue_test.go
index f3c5b50c8..7c6b05e81 100644
--- a/modules/convert/issue_test.go
+++ b/modules/convert/issue_test.go
@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/timeutil"
@@ -18,9 +19,9 @@ import (
 )
 
 func TestLabel_ToLabel(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
-	label := models.AssertExistsAndLoadBean(t, &models.Label{ID: 1}).(*models.Label)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: label.RepoID}).(*models.Repository)
+	assert.NoError(t, db.PrepareTestDatabase())
+	label := db.AssertExistsAndLoadBean(t, &models.Label{ID: 1}).(*models.Label)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: label.RepoID}).(*models.Repository)
 	assert.Equal(t, &api.Label{
 		ID:    label.ID,
 		Name:  label.Name,
diff --git a/modules/convert/main_test.go b/modules/convert/main_test.go
index 8720ff042..acb9802f9 100644
--- a/modules/convert/main_test.go
+++ b/modules/convert/main_test.go
@@ -8,9 +8,9 @@ import (
 	"path/filepath"
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", ".."))
+	db.MainTest(m, filepath.Join("..", ".."))
 }
diff --git a/modules/convert/pull_test.go b/modules/convert/pull_test.go
index adf42d8ca..655fc7632 100644
--- a/modules/convert/pull_test.go
+++ b/modules/convert/pull_test.go
@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
@@ -15,9 +16,9 @@ import (
 
 func TestPullRequest_APIFormat(t *testing.T) {
 	//with HeadRepo
-	assert.NoError(t, models.PrepareTestDatabase())
-	headRepo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	pr := models.AssertExistsAndLoadBean(t, &models.PullRequest{ID: 1}).(*models.PullRequest)
+	assert.NoError(t, db.PrepareTestDatabase())
+	headRepo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	pr := db.AssertExistsAndLoadBean(t, &models.PullRequest{ID: 1}).(*models.PullRequest)
 	assert.NoError(t, pr.LoadAttributes())
 	assert.NoError(t, pr.LoadIssue())
 	apiPullRequest := ToAPIPullRequest(pr)
@@ -31,7 +32,7 @@ func TestPullRequest_APIFormat(t *testing.T) {
 	}, apiPullRequest.Head)
 
 	//withOut HeadRepo
-	pr = models.AssertExistsAndLoadBean(t, &models.PullRequest{ID: 1}).(*models.PullRequest)
+	pr = db.AssertExistsAndLoadBean(t, &models.PullRequest{ID: 1}).(*models.PullRequest)
 	assert.NoError(t, pr.LoadIssue())
 	assert.NoError(t, pr.LoadAttributes())
 	// simulate fork deletion
diff --git a/modules/convert/user_test.go b/modules/convert/user_test.go
index 679c4f989..404adc202 100644
--- a/modules/convert/user_test.go
+++ b/modules/convert/user_test.go
@@ -8,20 +8,21 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestUser_ToUser(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user1 := models.AssertExistsAndLoadBean(t, &models.User{ID: 1, IsAdmin: true}).(*models.User)
+	user1 := db.AssertExistsAndLoadBean(t, &models.User{ID: 1, IsAdmin: true}).(*models.User)
 
 	apiUser := toUser(user1, true, true)
 	assert.True(t, apiUser.IsAdmin)
 
-	user2 := models.AssertExistsAndLoadBean(t, &models.User{ID: 2, IsAdmin: false}).(*models.User)
+	user2 := db.AssertExistsAndLoadBean(t, &models.User{ID: 2, IsAdmin: false}).(*models.User)
 
 	apiUser = toUser(user2, true, true)
 	assert.False(t, apiUser.IsAdmin)
@@ -30,7 +31,7 @@ func TestUser_ToUser(t *testing.T) {
 	assert.False(t, apiUser.IsAdmin)
 	assert.EqualValues(t, api.VisibleTypePublic.String(), apiUser.Visibility)
 
-	user31 := models.AssertExistsAndLoadBean(t, &models.User{ID: 31, IsAdmin: false, Visibility: api.VisibleTypePrivate}).(*models.User)
+	user31 := db.AssertExistsAndLoadBean(t, &models.User{ID: 31, IsAdmin: false, Visibility: api.VisibleTypePrivate}).(*models.User)
 
 	apiUser = toUser(user31, true, true)
 	assert.False(t, apiUser.IsAdmin)
diff --git a/modules/doctor/dbconsistency.go b/modules/doctor/dbconsistency.go
index 0d84c6397..fef3ae67a 100644
--- a/modules/doctor/dbconsistency.go
+++ b/modules/doctor/dbconsistency.go
@@ -8,6 +8,7 @@ import (
 	"context"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/models/migrations"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -15,7 +16,7 @@ import (
 
 func checkDBConsistency(logger log.Logger, autofix bool) error {
 	// make sure DB version is uptodate
-	if err := models.NewEngine(context.Background(), migrations.EnsureUpToDate); err != nil {
+	if err := db.NewEngine(context.Background(), migrations.EnsureUpToDate); err != nil {
 		logger.Critical("Model version on the database does not match the current Gitea version. Model consistency will not be checked until the database is upgraded")
 		return err
 	}
@@ -225,14 +226,14 @@ func checkDBConsistency(logger log.Logger, autofix bool) error {
 	// TODO: function to recalc all counters
 
 	if setting.Database.UsePostgreSQL {
-		count, err = models.CountBadSequences()
+		count, err = db.CountBadSequences()
 		if err != nil {
 			logger.Critical("Error: %v whilst checking sequence values", err)
 			return err
 		}
 		if count > 0 {
 			if autofix {
-				err := models.FixBadSequences()
+				err := db.FixBadSequences()
 				if err != nil {
 					logger.Critical("Error: %v whilst attempting to fix sequences", err)
 					return err
diff --git a/modules/doctor/dbversion.go b/modules/doctor/dbversion.go
index c5cac3bf9..acc564bdb 100644
--- a/modules/doctor/dbversion.go
+++ b/modules/doctor/dbversion.go
@@ -7,13 +7,13 @@ package doctor
 import (
 	"context"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/models/migrations"
 	"code.gitea.io/gitea/modules/log"
 )
 
 func checkDBVersion(logger log.Logger, autofix bool) error {
-	if err := models.NewEngine(context.Background(), migrations.EnsureUpToDate); err != nil {
+	if err := db.NewEngine(context.Background(), migrations.EnsureUpToDate); err != nil {
 		if !autofix {
 			logger.Critical("Error: %v during ensure up to date", err)
 			return err
@@ -21,7 +21,7 @@ func checkDBVersion(logger log.Logger, autofix bool) error {
 		logger.Warn("Got Error: %v during ensure up to date", err)
 		logger.Warn("Attempting to migrate to the latest DB version to fix this.")
 
-		err = models.NewEngine(context.Background(), migrations.Migrate)
+		err = db.NewEngine(context.Background(), migrations.Migrate)
 		if err != nil {
 			logger.Critical("Error: %v during migration", err)
 		}
diff --git a/modules/doctor/doctor.go b/modules/doctor/doctor.go
index 8c0d46730..d5cc4a185 100644
--- a/modules/doctor/doctor.go
+++ b/modules/doctor/doctor.go
@@ -9,7 +9,7 @@ import (
 	"sort"
 	"strings"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 )
@@ -47,7 +47,7 @@ func initDBDisableConsole(disableConsole bool) error {
 	setting.InitDBConfig()
 
 	setting.NewXORMLogService(disableConsole)
-	if err := models.SetEngine(); err != nil {
+	if err := db.SetEngine(); err != nil {
 		return fmt.Errorf("models.SetEngine: %v", err)
 	}
 	return nil
diff --git a/modules/doctor/mergebase.go b/modules/doctor/mergebase.go
index 7e9a065b7..e792c2b2f 100644
--- a/modules/doctor/mergebase.go
+++ b/modules/doctor/mergebase.go
@@ -9,14 +9,16 @@ import (
 	"strings"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
+
 	"xorm.io/builder"
 )
 
 func iteratePRs(repo *models.Repository, each func(*models.Repository, *models.PullRequest) error) error {
-	return models.Iterate(
-		models.DefaultDBContext(),
+	return db.Iterate(
+		db.DefaultContext(),
 		new(models.PullRequest),
 		builder.Eq{"base_repo_id": repo.ID},
 		func(idx int, bean interface{}) error {
diff --git a/modules/doctor/misc.go b/modules/doctor/misc.go
index 47fee8f7f..25bc3c3a7 100644
--- a/modules/doctor/misc.go
+++ b/modules/doctor/misc.go
@@ -12,19 +12,21 @@ import (
 	"strings"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/repository"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/util"
+
 	lru "github.com/hashicorp/golang-lru"
 	"xorm.io/builder"
 )
 
 func iterateRepositories(each func(*models.Repository) error) error {
-	err := models.Iterate(
-		models.DefaultDBContext(),
+	err := db.Iterate(
+		db.DefaultContext(),
 		new(models.Repository),
 		builder.Gt{"id": 0},
 		func(idx int, bean interface{}) error {
diff --git a/modules/indexer/code/bleve_test.go b/modules/indexer/code/bleve_test.go
index f79957220..1199dc98a 100644
--- a/modules/indexer/code/bleve_test.go
+++ b/modules/indexer/code/bleve_test.go
@@ -8,14 +8,14 @@ import (
 	"io/ioutil"
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/util"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestBleveIndexAndSearch(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 
 	dir, err := ioutil.TempDir("", "bleve.index")
 	assert.NoError(t, err)
diff --git a/modules/indexer/code/elastic_search_test.go b/modules/indexer/code/elastic_search_test.go
index 7cf62e0c5..c9d2c297b 100644
--- a/modules/indexer/code/elastic_search_test.go
+++ b/modules/indexer/code/elastic_search_test.go
@@ -8,13 +8,12 @@ import (
 	"os"
 	"testing"
 
-	"code.gitea.io/gitea/models"
-
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestESIndexAndSearch(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 
 	u := os.Getenv("TEST_INDEXER_CODE_ES_URL")
 	if u == "" {
diff --git a/modules/indexer/code/indexer.go b/modules/indexer/code/indexer.go
index 67fa43eda..46b590505 100644
--- a/modules/indexer/code/indexer.go
+++ b/modules/indexer/code/indexer.go
@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/graceful"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/queue"
@@ -285,7 +286,7 @@ func UpdateRepoIndexer(repo *models.Repository) {
 func populateRepoIndexer(ctx context.Context) {
 	log.Info("Populating the repo indexer with existing repositories")
 
-	exist, err := models.IsTableNotEmpty("repository")
+	exist, err := db.IsTableNotEmpty("repository")
 	if err != nil {
 		log.Fatal("System error: %v", err)
 	} else if !exist {
@@ -295,12 +296,12 @@ func populateRepoIndexer(ctx context.Context) {
 	// if there is any existing repo indexer metadata in the DB, delete it
 	// since we are starting afresh. Also, xorm requires deletes to have a
 	// condition, and we want to delete everything, thus 1=1.
-	if err := models.DeleteAllRecords("repo_indexer_status"); err != nil {
+	if err := db.DeleteAllRecords("repo_indexer_status"); err != nil {
 		log.Fatal("System error: %v", err)
 	}
 
 	var maxRepoID int64
-	if maxRepoID, err = models.GetMaxID("repository"); err != nil {
+	if maxRepoID, err = db.GetMaxID("repository"); err != nil {
 		log.Fatal("System error: %v", err)
 	}
 
diff --git a/modules/indexer/code/indexer_test.go b/modules/indexer/code/indexer_test.go
index 01717bd28..34930a84c 100644
--- a/modules/indexer/code/indexer_test.go
+++ b/modules/indexer/code/indexer_test.go
@@ -8,13 +8,12 @@ import (
 	"path/filepath"
 	"testing"
 
-	"code.gitea.io/gitea/models"
-
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", "..", ".."))
+	db.MainTest(m, filepath.Join("..", "..", ".."))
 }
 
 func testIndexer(name string, t *testing.T, indexer Indexer) {
diff --git a/modules/indexer/issues/indexer_test.go b/modules/indexer/issues/indexer_test.go
index 8c163f78d..1431115b8 100644
--- a/modules/indexer/issues/indexer_test.go
+++ b/modules/indexer/issues/indexer_test.go
@@ -11,7 +11,7 @@ import (
 	"testing"
 	"time"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
 
@@ -21,11 +21,11 @@ import (
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", "..", ".."))
+	db.MainTest(m, filepath.Join("..", "..", ".."))
 }
 
 func TestBleveSearchIssues(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	setting.Cfg = ini.Empty()
 
 	tmpIndexerDir, err := ioutil.TempDir("", "issues-indexer")
@@ -74,7 +74,7 @@ func TestBleveSearchIssues(t *testing.T) {
 }
 
 func TestDBSearchIssues(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	setting.Indexer.IssueType = "db"
 	InitIssueIndexer(true)
diff --git a/modules/indexer/stats/indexer.go b/modules/indexer/stats/indexer.go
index 4d8a174ff..fe87a2268 100644
--- a/modules/indexer/stats/indexer.go
+++ b/modules/indexer/stats/indexer.go
@@ -6,6 +6,7 @@ package stats
 
 import (
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/graceful"
 	"code.gitea.io/gitea/modules/log"
 )
@@ -39,7 +40,7 @@ func populateRepoIndexer() {
 
 	isShutdown := graceful.GetManager().IsShutdown()
 
-	exist, err := models.IsTableNotEmpty("repository")
+	exist, err := db.IsTableNotEmpty("repository")
 	if err != nil {
 		log.Fatal("System error: %v", err)
 	} else if !exist {
@@ -47,7 +48,7 @@ func populateRepoIndexer() {
 	}
 
 	var maxRepoID int64
-	if maxRepoID, err = models.GetMaxID("repository"); err != nil {
+	if maxRepoID, err = db.GetMaxID("repository"); err != nil {
 		log.Fatal("System error: %v", err)
 	}
 
diff --git a/modules/indexer/stats/indexer_test.go b/modules/indexer/stats/indexer_test.go
index 4bcbaa942..a4645b208 100644
--- a/modules/indexer/stats/indexer_test.go
+++ b/modules/indexer/stats/indexer_test.go
@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 
 	"gopkg.in/ini.v1"
@@ -18,11 +19,11 @@ import (
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", "..", ".."))
+	db.MainTest(m, filepath.Join("..", "..", ".."))
 }
 
 func TestRepoStatsIndex(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	setting.Cfg = ini.Empty()
 
 	setting.NewQueueService()
diff --git a/modules/migrations/gitea_uploader.go b/modules/migrations/gitea_uploader.go
index f8fb52fa0..3e8d396ed 100644
--- a/modules/migrations/gitea_uploader.go
+++ b/modules/migrations/gitea_uploader.go
@@ -16,6 +16,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/migrations/base"
@@ -69,17 +70,17 @@ func NewGiteaLocalUploader(ctx context.Context, doer *models.User, repoOwner, re
 func (g *GiteaLocalUploader) MaxBatchInsertSize(tp string) int {
 	switch tp {
 	case "issue":
-		return models.MaxBatchInsertSize(new(models.Issue))
+		return db.MaxBatchInsertSize(new(models.Issue))
 	case "comment":
-		return models.MaxBatchInsertSize(new(models.Comment))
+		return db.MaxBatchInsertSize(new(models.Comment))
 	case "milestone":
-		return models.MaxBatchInsertSize(new(models.Milestone))
+		return db.MaxBatchInsertSize(new(models.Milestone))
 	case "label":
-		return models.MaxBatchInsertSize(new(models.Label))
+		return db.MaxBatchInsertSize(new(models.Label))
 	case "release":
-		return models.MaxBatchInsertSize(new(models.Release))
+		return db.MaxBatchInsertSize(new(models.Release))
 	case "pullrequest":
-		return models.MaxBatchInsertSize(new(models.PullRequest))
+		return db.MaxBatchInsertSize(new(models.PullRequest))
 	}
 	return 10
 }
diff --git a/modules/migrations/gitea_uploader_test.go b/modules/migrations/gitea_uploader_test.go
index 032393032..73293f1f8 100644
--- a/modules/migrations/gitea_uploader_test.go
+++ b/modules/migrations/gitea_uploader_test.go
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/graceful"
 	"code.gitea.io/gitea/modules/migrations/base"
 	"code.gitea.io/gitea/modules/structs"
@@ -23,9 +24,9 @@ func TestGiteaUploadRepo(t *testing.T) {
 	// FIXME: Since no accesskey or user/password will trigger rate limit of github, just skip
 	t.Skip()
 
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
 
 	var (
 		downloader = NewGithubDownloaderV3(context.Background(), "https://github.com", "", "", "", "go-xorm", "builder")
@@ -50,7 +51,7 @@ func TestGiteaUploadRepo(t *testing.T) {
 	}, nil)
 	assert.NoError(t, err)
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{OwnerID: user.ID, Name: repoName}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{OwnerID: user.ID, Name: repoName}).(*models.Repository)
 	assert.True(t, repo.HasWiki())
 	assert.EqualValues(t, models.RepositoryReady, repo.Status)
 
diff --git a/modules/migrations/main_test.go b/modules/migrations/main_test.go
index 86aee4e86..5b2923065 100644
--- a/modules/migrations/main_test.go
+++ b/modules/migrations/main_test.go
@@ -10,14 +10,14 @@ import (
 	"testing"
 	"time"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/migrations/base"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", ".."))
+	db.MainTest(m, filepath.Join("..", ".."))
 }
 
 func timePtr(t time.Time) *time.Time {
diff --git a/modules/migrations/migrate_test.go b/modules/migrations/migrate_test.go
index 98ee2dfc4..c050a9abc 100644
--- a/modules/migrations/migrate_test.go
+++ b/modules/migrations/migrate_test.go
@@ -9,16 +9,17 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestMigrateWhiteBlocklist(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	adminUser := models.AssertExistsAndLoadBean(t, &models.User{Name: "user1"}).(*models.User)
-	nonAdminUser := models.AssertExistsAndLoadBean(t, &models.User{Name: "user2"}).(*models.User)
+	adminUser := db.AssertExistsAndLoadBean(t, &models.User{Name: "user1"}).(*models.User)
+	nonAdminUser := db.AssertExistsAndLoadBean(t, &models.User{Name: "user2"}).(*models.User)
 
 	setting.Migrations.AllowedDomains = []string{"github.com"}
 	assert.NoError(t, Init())
diff --git a/modules/notification/action/action_test.go b/modules/notification/action/action_test.go
index cdfe4bd66..705a4fb2f 100644
--- a/modules/notification/action/action_test.go
+++ b/modules/notification/action/action_test.go
@@ -10,18 +10,19 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", "..", ".."))
+	db.MainTest(m, filepath.Join("..", "..", ".."))
 }
 
 func TestRenameRepoAction(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{OwnerID: user.ID}).(*models.Repository)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{OwnerID: user.ID}).(*models.Repository)
 	repo.Owner = user
 
 	oldRepoName := repo.Name
@@ -38,10 +39,10 @@ func TestRenameRepoAction(t *testing.T) {
 		IsPrivate: repo.IsPrivate,
 		Content:   oldRepoName,
 	}
-	models.AssertNotExistsBean(t, actionBean)
+	db.AssertNotExistsBean(t, actionBean)
 
 	NewNotifier().NotifyRenameRepository(user, repo, oldRepoName)
 
-	models.AssertExistsAndLoadBean(t, actionBean)
+	db.AssertExistsAndLoadBean(t, actionBean)
 	models.CheckConsistencyFor(t, &models.Action{})
 }
diff --git a/modules/repofiles/action_test.go b/modules/repofiles/action_test.go
index 97632df68..c29cfd686 100644
--- a/modules/repofiles/action_test.go
+++ b/modules/repofiles/action_test.go
@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/repository"
 	"code.gitea.io/gitea/modules/setting"
 
@@ -15,7 +16,7 @@ import (
 )
 
 func TestUpdateIssuesCommit(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	pushCommits := []*repository.PushCommit{
 		{
 			Sha1:           "abcdef1",
@@ -43,8 +44,8 @@ func TestUpdateIssuesCommit(t *testing.T) {
 		},
 	}
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 	repo.Owner = user
 
 	commentBean := &models.Comment{
@@ -55,11 +56,11 @@ func TestUpdateIssuesCommit(t *testing.T) {
 	}
 	issueBean := &models.Issue{RepoID: repo.ID, Index: 4}
 
-	models.AssertNotExistsBean(t, commentBean)
-	models.AssertNotExistsBean(t, &models.Issue{RepoID: repo.ID, Index: 2}, "is_closed=1")
+	db.AssertNotExistsBean(t, commentBean)
+	db.AssertNotExistsBean(t, &models.Issue{RepoID: repo.ID, Index: 2}, "is_closed=1")
 	assert.NoError(t, UpdateIssuesCommit(user, repo, pushCommits, repo.DefaultBranch))
-	models.AssertExistsAndLoadBean(t, commentBean)
-	models.AssertExistsAndLoadBean(t, issueBean, "is_closed=1")
+	db.AssertExistsAndLoadBean(t, commentBean)
+	db.AssertExistsAndLoadBean(t, issueBean, "is_closed=1")
 	models.CheckConsistencyFor(t, &models.Action{})
 
 	// Test that push to a non-default branch closes no issue.
@@ -73,7 +74,7 @@ func TestUpdateIssuesCommit(t *testing.T) {
 			Message:        "close #1",
 		},
 	}
-	repo = models.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)
+	repo = db.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)
 	commentBean = &models.Comment{
 		Type:      models.CommentTypeCommitRef,
 		CommitSHA: "abcdef1",
@@ -82,11 +83,11 @@ func TestUpdateIssuesCommit(t *testing.T) {
 	}
 	issueBean = &models.Issue{RepoID: repo.ID, Index: 1}
 
-	models.AssertNotExistsBean(t, commentBean)
-	models.AssertNotExistsBean(t, &models.Issue{RepoID: repo.ID, Index: 1}, "is_closed=1")
+	db.AssertNotExistsBean(t, commentBean)
+	db.AssertNotExistsBean(t, &models.Issue{RepoID: repo.ID, Index: 1}, "is_closed=1")
 	assert.NoError(t, UpdateIssuesCommit(user, repo, pushCommits, "non-existing-branch"))
-	models.AssertExistsAndLoadBean(t, commentBean)
-	models.AssertNotExistsBean(t, issueBean, "is_closed=1")
+	db.AssertExistsAndLoadBean(t, commentBean)
+	db.AssertNotExistsBean(t, issueBean, "is_closed=1")
 	models.CheckConsistencyFor(t, &models.Action{})
 
 	pushCommits = []*repository.PushCommit{
@@ -99,7 +100,7 @@ func TestUpdateIssuesCommit(t *testing.T) {
 			Message:        "close " + setting.AppURL + repo.FullName() + "/pulls/1",
 		},
 	}
-	repo = models.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)
+	repo = db.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)
 	commentBean = &models.Comment{
 		Type:      models.CommentTypeCommitRef,
 		CommitSHA: "abcdef3",
@@ -108,16 +109,16 @@ func TestUpdateIssuesCommit(t *testing.T) {
 	}
 	issueBean = &models.Issue{RepoID: repo.ID, Index: 1}
 
-	models.AssertNotExistsBean(t, commentBean)
-	models.AssertNotExistsBean(t, &models.Issue{RepoID: repo.ID, Index: 1}, "is_closed=1")
+	db.AssertNotExistsBean(t, commentBean)
+	db.AssertNotExistsBean(t, &models.Issue{RepoID: repo.ID, Index: 1}, "is_closed=1")
 	assert.NoError(t, UpdateIssuesCommit(user, repo, pushCommits, repo.DefaultBranch))
-	models.AssertExistsAndLoadBean(t, commentBean)
-	models.AssertExistsAndLoadBean(t, issueBean, "is_closed=1")
+	db.AssertExistsAndLoadBean(t, commentBean)
+	db.AssertExistsAndLoadBean(t, issueBean, "is_closed=1")
 	models.CheckConsistencyFor(t, &models.Action{})
 }
 
 func TestUpdateIssuesCommit_Colon(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	pushCommits := []*repository.PushCommit{
 		{
 			Sha1:           "abcdef2",
@@ -129,21 +130,21 @@ func TestUpdateIssuesCommit_Colon(t *testing.T) {
 		},
 	}
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 	repo.Owner = user
 
 	issueBean := &models.Issue{RepoID: repo.ID, Index: 4}
 
-	models.AssertNotExistsBean(t, &models.Issue{RepoID: repo.ID, Index: 2}, "is_closed=1")
+	db.AssertNotExistsBean(t, &models.Issue{RepoID: repo.ID, Index: 2}, "is_closed=1")
 	assert.NoError(t, UpdateIssuesCommit(user, repo, pushCommits, repo.DefaultBranch))
-	models.AssertExistsAndLoadBean(t, issueBean, "is_closed=1")
+	db.AssertExistsAndLoadBean(t, issueBean, "is_closed=1")
 	models.CheckConsistencyFor(t, &models.Action{})
 }
 
 func TestUpdateIssuesCommit_Issue5957(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 
 	// Test that push to a non-default branch closes an issue.
 	pushCommits := []*repository.PushCommit{
@@ -157,7 +158,7 @@ func TestUpdateIssuesCommit_Issue5957(t *testing.T) {
 		},
 	}
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 2}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 2}).(*models.Repository)
 	commentBean := &models.Comment{
 		Type:      models.CommentTypeCommitRef,
 		CommitSHA: "abcdef1",
@@ -167,17 +168,17 @@ func TestUpdateIssuesCommit_Issue5957(t *testing.T) {
 
 	issueBean := &models.Issue{RepoID: repo.ID, Index: 2, ID: 7}
 
-	models.AssertNotExistsBean(t, commentBean)
-	models.AssertNotExistsBean(t, issueBean, "is_closed=1")
+	db.AssertNotExistsBean(t, commentBean)
+	db.AssertNotExistsBean(t, issueBean, "is_closed=1")
 	assert.NoError(t, UpdateIssuesCommit(user, repo, pushCommits, "non-existing-branch"))
-	models.AssertExistsAndLoadBean(t, commentBean)
-	models.AssertExistsAndLoadBean(t, issueBean, "is_closed=1")
+	db.AssertExistsAndLoadBean(t, commentBean)
+	db.AssertExistsAndLoadBean(t, issueBean, "is_closed=1")
 	models.CheckConsistencyFor(t, &models.Action{})
 }
 
 func TestUpdateIssuesCommit_AnotherRepo(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 
 	// Test that a push to default branch closes issue in another repo
 	// If the user also has push permissions to that repo
@@ -192,7 +193,7 @@ func TestUpdateIssuesCommit_AnotherRepo(t *testing.T) {
 		},
 	}
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 2}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 2}).(*models.Repository)
 	commentBean := &models.Comment{
 		Type:      models.CommentTypeCommitRef,
 		CommitSHA: "abcdef1",
@@ -202,17 +203,17 @@ func TestUpdateIssuesCommit_AnotherRepo(t *testing.T) {
 
 	issueBean := &models.Issue{RepoID: 1, Index: 1, ID: 1}
 
-	models.AssertNotExistsBean(t, commentBean)
-	models.AssertNotExistsBean(t, issueBean, "is_closed=1")
+	db.AssertNotExistsBean(t, commentBean)
+	db.AssertNotExistsBean(t, issueBean, "is_closed=1")
 	assert.NoError(t, UpdateIssuesCommit(user, repo, pushCommits, repo.DefaultBranch))
-	models.AssertExistsAndLoadBean(t, commentBean)
-	models.AssertExistsAndLoadBean(t, issueBean, "is_closed=1")
+	db.AssertExistsAndLoadBean(t, commentBean)
+	db.AssertExistsAndLoadBean(t, issueBean, "is_closed=1")
 	models.CheckConsistencyFor(t, &models.Action{})
 }
 
 func TestUpdateIssuesCommit_AnotherRepo_FullAddress(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 
 	// Test that a push to default branch closes issue in another repo
 	// If the user also has push permissions to that repo
@@ -227,7 +228,7 @@ func TestUpdateIssuesCommit_AnotherRepo_FullAddress(t *testing.T) {
 		},
 	}
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 2}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 2}).(*models.Repository)
 	commentBean := &models.Comment{
 		Type:      models.CommentTypeCommitRef,
 		CommitSHA: "abcdef1",
@@ -237,17 +238,17 @@ func TestUpdateIssuesCommit_AnotherRepo_FullAddress(t *testing.T) {
 
 	issueBean := &models.Issue{RepoID: 1, Index: 1, ID: 1}
 
-	models.AssertNotExistsBean(t, commentBean)
-	models.AssertNotExistsBean(t, issueBean, "is_closed=1")
+	db.AssertNotExistsBean(t, commentBean)
+	db.AssertNotExistsBean(t, issueBean, "is_closed=1")
 	assert.NoError(t, UpdateIssuesCommit(user, repo, pushCommits, repo.DefaultBranch))
-	models.AssertExistsAndLoadBean(t, commentBean)
-	models.AssertExistsAndLoadBean(t, issueBean, "is_closed=1")
+	db.AssertExistsAndLoadBean(t, commentBean)
+	db.AssertExistsAndLoadBean(t, issueBean, "is_closed=1")
 	models.CheckConsistencyFor(t, &models.Action{})
 }
 
 func TestUpdateIssuesCommit_AnotherRepoNoPermission(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 10}).(*models.User)
+	assert.NoError(t, db.PrepareTestDatabase())
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 10}).(*models.User)
 
 	// Test that a push with close reference *can not* close issue
 	// If the committer doesn't have push rights in that repo
@@ -270,7 +271,7 @@ func TestUpdateIssuesCommit_AnotherRepoNoPermission(t *testing.T) {
 		},
 	}
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 6}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 6}).(*models.Repository)
 	commentBean := &models.Comment{
 		Type:      models.CommentTypeCommitRef,
 		CommitSHA: "abcdef3",
@@ -286,12 +287,12 @@ func TestUpdateIssuesCommit_AnotherRepoNoPermission(t *testing.T) {
 
 	issueBean := &models.Issue{RepoID: 3, Index: 1, ID: 6}
 
-	models.AssertNotExistsBean(t, commentBean)
-	models.AssertNotExistsBean(t, commentBean2)
-	models.AssertNotExistsBean(t, issueBean, "is_closed=1")
+	db.AssertNotExistsBean(t, commentBean)
+	db.AssertNotExistsBean(t, commentBean2)
+	db.AssertNotExistsBean(t, issueBean, "is_closed=1")
 	assert.NoError(t, UpdateIssuesCommit(user, repo, pushCommits, repo.DefaultBranch))
-	models.AssertNotExistsBean(t, commentBean)
-	models.AssertNotExistsBean(t, commentBean2)
-	models.AssertNotExistsBean(t, issueBean, "is_closed=1")
+	db.AssertNotExistsBean(t, commentBean)
+	db.AssertNotExistsBean(t, commentBean2)
+	db.AssertNotExistsBean(t, issueBean, "is_closed=1")
 	models.CheckConsistencyFor(t, &models.Action{})
 }
diff --git a/modules/repofiles/blob_test.go b/modules/repofiles/blob_test.go
index 8ba80347b..5238dd6e7 100644
--- a/modules/repofiles/blob_test.go
+++ b/modules/repofiles/blob_test.go
@@ -7,7 +7,7 @@ package repofiles
 import (
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/test"
 
@@ -15,7 +15,7 @@ import (
 )
 
 func TestGetBlobBySHA(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1")
 	test.LoadRepo(t, ctx, 1)
 	test.LoadRepoCommit(t, ctx)
diff --git a/modules/repofiles/content_test.go b/modules/repofiles/content_test.go
index 253d43445..f68460d7e 100644
--- a/modules/repofiles/content_test.go
+++ b/modules/repofiles/content_test.go
@@ -8,7 +8,7 @@ import (
 	"path/filepath"
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/test"
 
@@ -16,7 +16,7 @@ import (
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", ".."))
+	db.MainTest(m, filepath.Join("..", ".."))
 }
 
 func getExpectedReadmeContentsResponse() *api.ContentsResponse {
@@ -49,7 +49,7 @@ func getExpectedReadmeContentsResponse() *api.ContentsResponse {
 }
 
 func TestGetContents(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1")
 	ctx.SetParams(":id", "1")
 	test.LoadRepo(t, ctx, 1)
@@ -77,7 +77,7 @@ func TestGetContents(t *testing.T) {
 }
 
 func TestGetContentsOrListForDir(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1")
 	ctx.SetParams(":id", "1")
 	test.LoadRepo(t, ctx, 1)
@@ -112,7 +112,7 @@ func TestGetContentsOrListForDir(t *testing.T) {
 }
 
 func TestGetContentsOrListForFile(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1")
 	ctx.SetParams(":id", "1")
 	test.LoadRepo(t, ctx, 1)
@@ -140,7 +140,7 @@ func TestGetContentsOrListForFile(t *testing.T) {
 }
 
 func TestGetContentsErrors(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1")
 	ctx.SetParams(":id", "1")
 	test.LoadRepo(t, ctx, 1)
@@ -171,7 +171,7 @@ func TestGetContentsErrors(t *testing.T) {
 }
 
 func TestGetContentsOrListErrors(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1")
 	ctx.SetParams(":id", "1")
 	test.LoadRepo(t, ctx, 1)
@@ -202,7 +202,7 @@ func TestGetContentsOrListErrors(t *testing.T) {
 }
 
 func TestGetContentsOrListOfEmptyRepos(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo15")
 	ctx.SetParams(":id", "15")
 	test.LoadRepo(t, ctx, 15)
diff --git a/modules/repofiles/diff_test.go b/modules/repofiles/diff_test.go
index da5028415..aeb4f76a4 100644
--- a/modules/repofiles/diff_test.go
+++ b/modules/repofiles/diff_test.go
@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/test"
 	"code.gitea.io/gitea/services/gitdiff"
 
@@ -15,7 +16,7 @@ import (
 )
 
 func TestGetDiffPreview(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1")
 	ctx.SetParams(":id", "1")
 	test.LoadRepo(t, ctx, 1)
@@ -128,7 +129,7 @@ func TestGetDiffPreview(t *testing.T) {
 }
 
 func TestGetDiffPreviewErrors(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1")
 	ctx.SetParams(":id", "1")
 	test.LoadRepo(t, ctx, 1)
diff --git a/modules/repofiles/file_test.go b/modules/repofiles/file_test.go
index aafe816a1..297405654 100644
--- a/modules/repofiles/file_test.go
+++ b/modules/repofiles/file_test.go
@@ -7,7 +7,7 @@ package repofiles
 import (
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
@@ -81,7 +81,7 @@ func getExpectedFileResponse() *api.FileResponse {
 }
 
 func TestGetFileResponseFromCommit(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1")
 	ctx.SetParams(":id", "1")
 	test.LoadRepo(t, ctx, 1)
diff --git a/modules/repofiles/tree_test.go b/modules/repofiles/tree_test.go
index 274e89e96..9e2efa421 100644
--- a/modules/repofiles/tree_test.go
+++ b/modules/repofiles/tree_test.go
@@ -7,7 +7,7 @@ package repofiles
 import (
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/test"
 
@@ -15,7 +15,7 @@ import (
 )
 
 func TestGetTreeBySHA(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1")
 	test.LoadRepo(t, ctx, 1)
 	test.LoadRepoCommit(t, ctx)
diff --git a/modules/repository/adopt.go b/modules/repository/adopt.go
index 321e6ab76..9371822fb 100644
--- a/modules/repository/adopt.go
+++ b/modules/repository/adopt.go
@@ -11,6 +11,7 @@ import (
 	"strings"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -46,7 +47,7 @@ func AdoptRepository(doer, u *models.User, opts models.CreateRepoOptions) (*mode
 		IsEmpty:                         !opts.AutoInit,
 	}
 
-	if err := models.WithTx(func(ctx models.DBContext) error {
+	if err := db.WithTx(func(ctx *db.Context) error {
 		repoPath := models.RepoPath(u.Name, repo.Name)
 		isExist, err := util.IsExist(repoPath)
 		if err != nil {
diff --git a/modules/repository/check.go b/modules/repository/check.go
index 0485e9e83..1b550ad4f 100644
--- a/modules/repository/check.go
+++ b/modules/repository/check.go
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/util"
@@ -22,8 +23,8 @@ import (
 func GitFsck(ctx context.Context, timeout time.Duration, args []string) error {
 	log.Trace("Doing: GitFsck")
 
-	if err := models.Iterate(
-		models.DefaultDBContext(),
+	if err := db.Iterate(
+		db.DefaultContext(),
 		new(models.Repository),
 		builder.Expr("id>0 AND is_fsck_enabled=?", true),
 		func(idx int, bean interface{}) error {
@@ -57,8 +58,8 @@ func GitGcRepos(ctx context.Context, timeout time.Duration, args ...string) erro
 	log.Trace("Doing: GitGcRepos")
 	args = append([]string{"gc"}, args...)
 
-	if err := models.Iterate(
-		models.DefaultDBContext(),
+	if err := db.Iterate(
+		db.DefaultContext(),
 		new(models.Repository),
 		builder.Gt{"id": 0},
 		func(idx int, bean interface{}) error {
@@ -93,7 +94,7 @@ func GitGcRepos(ctx context.Context, timeout time.Duration, args ...string) erro
 			}
 
 			// Now update the size of the repository
-			if err := repo.UpdateSize(models.DefaultDBContext()); err != nil {
+			if err := repo.UpdateSize(db.DefaultContext()); err != nil {
 				log.Error("Updating size as part of garbage collection failed for %v. Stdout: %s\nError: %v", repo, stdout, err)
 				desc := fmt.Sprintf("Updating size as part of garbage collection failed for %s. Stdout: %s\nError: %v", repo.RepoPath(), stdout, err)
 				if err = models.CreateRepositoryNotice(desc); err != nil {
@@ -114,8 +115,8 @@ func GitGcRepos(ctx context.Context, timeout time.Duration, args ...string) erro
 
 func gatherMissingRepoRecords(ctx context.Context) ([]*models.Repository, error) {
 	repos := make([]*models.Repository, 0, 10)
-	if err := models.Iterate(
-		models.DefaultDBContext(),
+	if err := db.Iterate(
+		db.DefaultContext(),
 		new(models.Repository),
 		builder.Gt{"id": 0},
 		func(idx int, bean interface{}) error {
diff --git a/modules/repository/commits_test.go b/modules/repository/commits_test.go
index 9f0852525..c62ad5844 100644
--- a/modules/repository/commits_test.go
+++ b/modules/repository/commits_test.go
@@ -11,12 +11,13 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestPushCommits_ToAPIPayloadCommits(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	pushCommits := NewPushCommits()
 	pushCommits.Commits = []*PushCommit{
@@ -47,7 +48,7 @@ func TestPushCommits_ToAPIPayloadCommits(t *testing.T) {
 	}
 	pushCommits.HeadCommit = &PushCommit{Sha1: "69554a6"}
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 16}).(*models.Repository)
 	payloadCommits, headCommit, err := pushCommits.ToAPIPayloadCommits(repo.RepoPath(), "/user2/repo16")
 	assert.NoError(t, err)
 	assert.Len(t, payloadCommits, 3)
@@ -99,7 +100,7 @@ func TestPushCommits_ToAPIPayloadCommits(t *testing.T) {
 }
 
 func TestPushCommits_AvatarLink(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	pushCommits := NewPushCommits()
 	pushCommits.Commits = []*PushCommit{
diff --git a/modules/repository/create.go b/modules/repository/create.go
index 5eac03836..80f446e83 100644
--- a/modules/repository/create.go
+++ b/modules/repository/create.go
@@ -9,6 +9,7 @@ import (
 	"strings"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -54,7 +55,7 @@ func CreateRepository(doer, u *models.User, opts models.CreateRepoOptions) (*mod
 
 	var rollbackRepo *models.Repository
 
-	if err := models.WithTx(func(ctx models.DBContext) error {
+	if err := db.WithTx(func(ctx *db.Context) error {
 		if err := models.CreateRepository(ctx, doer, u, repo, false); err != nil {
 			return err
 		}
diff --git a/modules/repository/create_test.go b/modules/repository/create_test.go
index 65ed7806a..040c061d9 100644
--- a/modules/repository/create_test.go
+++ b/modules/repository/create_test.go
@@ -9,16 +9,17 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/structs"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestIncludesAllRepositoriesTeams(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	testTeamRepositories := func(teamID int64, repoIds []int64) {
-		team := models.AssertExistsAndLoadBean(t, &models.Team{ID: teamID}).(*models.Team)
+		team := db.AssertExistsAndLoadBean(t, &models.Team{ID: teamID}).(*models.Team)
 		assert.NoError(t, team.GetRepositories(&models.SearchTeamOptions{}), "%s: GetRepositories", team.Name)
 		assert.Len(t, team.Repos, team.NumRepos, "%s: len repo", team.Name)
 		assert.Len(t, team.Repos, len(repoIds), "%s: repo count", team.Name)
diff --git a/modules/repository/fork.go b/modules/repository/fork.go
index b154cc5cc..ff69f75b3 100644
--- a/modules/repository/fork.go
+++ b/modules/repository/fork.go
@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/structs"
@@ -78,7 +79,7 @@ func ForkRepository(doer, owner *models.User, opts models.ForkRepoOptions) (_ *m
 		panic(panicErr)
 	}()
 
-	err = models.WithTx(func(ctx models.DBContext) error {
+	err = db.WithTx(func(ctx *db.Context) error {
 		if err = models.CreateRepository(ctx, doer, owner, repo, false); err != nil {
 			return err
 		}
@@ -122,7 +123,7 @@ func ForkRepository(doer, owner *models.User, opts models.ForkRepoOptions) (_ *m
 	}
 
 	// even if below operations failed, it could be ignored. And they will be retried
-	ctx := models.DefaultDBContext()
+	ctx := db.DefaultContext()
 	if err := repo.UpdateSize(ctx); err != nil {
 		log.Error("Failed to update size for repository: %v", err)
 	}
@@ -135,7 +136,7 @@ func ForkRepository(doer, owner *models.User, opts models.ForkRepoOptions) (_ *m
 
 // ConvertForkToNormalRepository convert the provided repo from a forked repo to normal repo
 func ConvertForkToNormalRepository(repo *models.Repository) error {
-	err := models.WithTx(func(ctx models.DBContext) error {
+	err := db.WithTx(func(ctx *db.Context) error {
 		repo, err := models.GetRepositoryByIDCtx(ctx, repo.ID)
 		if err != nil {
 			return err
diff --git a/modules/repository/fork_test.go b/modules/repository/fork_test.go
index fc4a72466..7a05f9dd9 100644
--- a/modules/repository/fork_test.go
+++ b/modules/repository/fork_test.go
@@ -8,15 +8,16 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestForkRepository(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// user 13 has already forked repo10
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 13}).(*models.User)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 10}).(*models.Repository)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 13}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 10}).(*models.Repository)
 
 	fork, err := ForkRepository(user, user, models.ForkRepoOptions{
 		BaseRepo:    repo,
diff --git a/modules/repository/generate.go b/modules/repository/generate.go
index 1ba457fb3..6ac2a3051 100644
--- a/modules/repository/generate.go
+++ b/modules/repository/generate.go
@@ -14,6 +14,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/util"
@@ -185,7 +186,7 @@ func generateRepoCommit(repo, templateRepo, generateRepo *models.Repository, tmp
 	return initRepoCommit(tmpDir, repo, repo.Owner, templateRepo.DefaultBranch)
 }
 
-func generateGitContent(ctx models.DBContext, repo, templateRepo, generateRepo *models.Repository) (err error) {
+func generateGitContent(ctx *db.Context, repo, templateRepo, generateRepo *models.Repository) (err error) {
 	tmpDir, err := ioutil.TempDir(os.TempDir(), "gitea-"+repo.Name)
 	if err != nil {
 		return fmt.Errorf("Failed to create temp dir for repository %s: %v", repo.RepoPath(), err)
@@ -223,7 +224,7 @@ func generateGitContent(ctx models.DBContext, repo, templateRepo, generateRepo *
 }
 
 // GenerateGitContent generates git content from a template repository
-func GenerateGitContent(ctx models.DBContext, templateRepo, generateRepo *models.Repository) error {
+func GenerateGitContent(ctx *db.Context, templateRepo, generateRepo *models.Repository) error {
 	if err := generateGitContent(ctx, generateRepo, templateRepo, generateRepo); err != nil {
 		return err
 	}
@@ -239,7 +240,7 @@ func GenerateGitContent(ctx models.DBContext, templateRepo, generateRepo *models
 }
 
 // GenerateRepository generates a repository from a template
-func GenerateRepository(ctx models.DBContext, doer, owner *models.User, templateRepo *models.Repository, opts models.GenerateRepoOptions) (_ *models.Repository, err error) {
+func GenerateRepository(ctx *db.Context, doer, owner *models.User, templateRepo *models.Repository, opts models.GenerateRepoOptions) (_ *models.Repository, err error) {
 	generateRepo := &models.Repository{
 		OwnerID:       owner.ID,
 		Owner:         owner,
diff --git a/modules/repository/hooks.go b/modules/repository/hooks.go
index 8b4e7d630..de5df591f 100644
--- a/modules/repository/hooks.go
+++ b/modules/repository/hooks.go
@@ -12,6 +12,7 @@ import (
 	"path/filepath"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -220,8 +221,8 @@ func CheckDelegateHooks(repoPath string) ([]string, error) {
 func SyncRepositoryHooks(ctx context.Context) error {
 	log.Trace("Doing: SyncRepositoryHooks")
 
-	if err := models.Iterate(
-		models.DefaultDBContext(),
+	if err := db.Iterate(
+		db.DefaultContext(),
 		new(models.Repository),
 		builder.Gt{"id": 0},
 		func(idx int, bean interface{}) error {
diff --git a/modules/repository/init.go b/modules/repository/init.go
index 50cde4c0b..e42d35a97 100644
--- a/modules/repository/init.go
+++ b/modules/repository/init.go
@@ -14,6 +14,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -22,7 +23,7 @@ import (
 	"github.com/unknwon/com"
 )
 
-func prepareRepoCommit(ctx models.DBContext, repo *models.Repository, tmpDir, repoPath string, opts models.CreateRepoOptions) error {
+func prepareRepoCommit(ctx *db.Context, repo *models.Repository, tmpDir, repoPath string, opts models.CreateRepoOptions) error {
 	commitTimeStr := time.Now().Format(time.RFC3339)
 	authorSig := repo.Owner.NewGitSig()
 
@@ -196,7 +197,7 @@ func checkInitRepository(owner, name string) (err error) {
 	return nil
 }
 
-func adoptRepository(ctx models.DBContext, repoPath string, u *models.User, repo *models.Repository, opts models.CreateRepoOptions) (err error) {
+func adoptRepository(ctx *db.Context, repoPath string, u *models.User, repo *models.Repository, opts models.CreateRepoOptions) (err error) {
 	isExist, err := util.IsExist(repoPath)
 	if err != nil {
 		log.Error("Unable to check if %s exists. Error: %v", repoPath, err)
@@ -283,7 +284,7 @@ func adoptRepository(ctx models.DBContext, repoPath string, u *models.User, repo
 }
 
 // InitRepository initializes README and .gitignore if needed.
-func initRepository(ctx models.DBContext, repoPath string, u *models.User, repo *models.Repository, opts models.CreateRepoOptions) (err error) {
+func initRepository(ctx *db.Context, repoPath string, u *models.User, repo *models.Repository, opts models.CreateRepoOptions) (err error) {
 	if err = checkInitRepository(repo.OwnerName, repo.Name); err != nil {
 		return err
 	}
diff --git a/modules/repository/main_test.go b/modules/repository/main_test.go
index f13f35863..91d0d36ca 100644
--- a/modules/repository/main_test.go
+++ b/modules/repository/main_test.go
@@ -8,9 +8,9 @@ import (
 	"path/filepath"
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", ".."))
+	db.MainTest(m, filepath.Join("..", ".."))
 }
diff --git a/modules/repository/repo.go b/modules/repository/repo.go
index 00413549e..b59a80ee2 100644
--- a/modules/repository/repo.go
+++ b/modules/repository/repo.go
@@ -14,6 +14,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/lfs"
 	"code.gitea.io/gitea/modules/log"
@@ -132,7 +133,7 @@ func MigrateRepositoryGitData(ctx context.Context, u *models.User, repo *models.
 		}
 	}
 
-	if err = repo.UpdateSize(models.DefaultDBContext()); err != nil {
+	if err = repo.UpdateSize(db.DefaultContext()); err != nil {
 		log.Error("Failed to update size for repository: %v", err)
 	}
 
diff --git a/modules/repository/update.go b/modules/repository/update.go
index 975f577da..d9ff12e1a 100644
--- a/modules/repository/update.go
+++ b/modules/repository/update.go
@@ -10,13 +10,14 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/timeutil"
 )
 
 // PushUpdateAddDeleteTags updates a number of added and delete tags
 func PushUpdateAddDeleteTags(repo *models.Repository, gitRepo *git.Repository, addTags, delTags []string) error {
-	return models.WithTx(func(ctx models.DBContext) error {
+	return db.WithTx(func(ctx *db.Context) error {
 		if err := models.PushUpdateDeleteTagsContext(ctx, repo, delTags); err != nil {
 			return err
 		}
@@ -25,7 +26,7 @@ func PushUpdateAddDeleteTags(repo *models.Repository, gitRepo *git.Repository, a
 }
 
 // pushUpdateAddTags updates a number of add tags
-func pushUpdateAddTags(ctx models.DBContext, repo *models.Repository, gitRepo *git.Repository, tags []string) error {
+func pushUpdateAddTags(ctx *db.Context, repo *models.Repository, gitRepo *git.Repository, tags []string) error {
 	if len(tags) == 0 {
 		return nil
 	}
diff --git a/modules/test/context_tests.go b/modules/test/context_tests.go
index a15c74d82..8a4d2d8bc 100644
--- a/modules/test/context_tests.go
+++ b/modules/test/context_tests.go
@@ -14,6 +14,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/web/middleware"
@@ -52,7 +53,7 @@ func MockContext(t *testing.T, path string) *context.Context {
 // LoadRepo load a repo into a test context.
 func LoadRepo(t *testing.T, ctx *context.Context, repoID int64) {
 	ctx.Repo = &context.Repository{}
-	ctx.Repo.Repository = models.AssertExistsAndLoadBean(t, &models.Repository{ID: repoID}).(*models.Repository)
+	ctx.Repo.Repository = db.AssertExistsAndLoadBean(t, &models.Repository{ID: repoID}).(*models.Repository)
 	var err error
 	ctx.Repo.Owner, err = models.GetUserByID(ctx.Repo.Repository.OwnerID)
 	assert.NoError(t, err)
@@ -77,7 +78,7 @@ func LoadRepoCommit(t *testing.T, ctx *context.Context) {
 
 // LoadUser load a user into a test context.
 func LoadUser(t *testing.T, ctx *context.Context, userID int64) {
-	ctx.User = models.AssertExistsAndLoadBean(t, &models.User{ID: userID}).(*models.User)
+	ctx.User = db.AssertExistsAndLoadBean(t, &models.User{ID: userID}).(*models.User)
 }
 
 // LoadGitRepo load a git repo into a test context. Requires that ctx.Repo has
diff --git a/routers/api/v1/repo/hook_test.go b/routers/api/v1/repo/hook_test.go
index 8ed4bc4b0..79b8ec171 100644
--- a/routers/api/v1/repo/hook_test.go
+++ b/routers/api/v1/repo/hook_test.go
@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/test"
 
@@ -16,7 +17,7 @@ import (
 )
 
 func TestTestHook(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 
 	ctx := test.MockContext(t, "user2/repo1/wiki/_pages")
 	ctx.SetParams(":id", "1")
@@ -26,8 +27,8 @@ func TestTestHook(t *testing.T) {
 	TestHook(&context.APIContext{Context: ctx, Org: nil})
 	assert.EqualValues(t, http.StatusNoContent, ctx.Resp.Status())
 
-	models.AssertExistsAndLoadBean(t, &models.HookTask{
+	db.AssertExistsAndLoadBean(t, &models.HookTask{
 		RepoID: 1,
 		HookID: 1,
-	}, models.Cond("is_delivered=?", false))
+	}, db.Cond("is_delivered=?", false))
 }
diff --git a/routers/api/v1/repo/main_test.go b/routers/api/v1/repo/main_test.go
index 656758ffb..7a66370e0 100644
--- a/routers/api/v1/repo/main_test.go
+++ b/routers/api/v1/repo/main_test.go
@@ -8,9 +8,9 @@ import (
 	"path/filepath"
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", "..", "..", ".."))
+	db.MainTest(m, filepath.Join("..", "..", "..", ".."))
 }
diff --git a/routers/api/v1/repo/repo_test.go b/routers/api/v1/repo/repo_test.go
index a1bd3e85d..e4fd4f942 100644
--- a/routers/api/v1/repo/repo_test.go
+++ b/routers/api/v1/repo/repo_test.go
@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/context"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/test"
@@ -18,7 +19,7 @@ import (
 )
 
 func TestRepoEdit(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 
 	ctx := test.MockContext(t, "user2/repo1")
 	test.LoadRepo(t, ctx, 1)
@@ -59,13 +60,13 @@ func TestRepoEdit(t *testing.T) {
 	Edit(apiCtx)
 
 	assert.EqualValues(t, http.StatusOK, ctx.Resp.Status())
-	models.AssertExistsAndLoadBean(t, &models.Repository{
+	db.AssertExistsAndLoadBean(t, &models.Repository{
 		ID: 1,
-	}, models.Cond("name = ? AND is_archived = 1", *opts.Name))
+	}, db.Cond("name = ? AND is_archived = 1", *opts.Name))
 }
 
 func TestRepoEditNameChange(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 
 	ctx := test.MockContext(t, "user2/repo1")
 	test.LoadRepo(t, ctx, 1)
@@ -81,7 +82,7 @@ func TestRepoEditNameChange(t *testing.T) {
 	Edit(apiCtx)
 	assert.EqualValues(t, http.StatusOK, ctx.Resp.Status())
 
-	models.AssertExistsAndLoadBean(t, &models.Repository{
+	db.AssertExistsAndLoadBean(t, &models.Repository{
 		ID: 1,
-	}, models.Cond("name = ?", opts.Name))
+	}, db.Cond("name = ?", opts.Name))
 }
diff --git a/routers/common/db.go b/routers/common/db.go
index 069a46f64..e5848796f 100644
--- a/routers/common/db.go
+++ b/routers/common/db.go
@@ -9,7 +9,7 @@ import (
 	"fmt"
 	"time"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/models/migrations"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
@@ -25,7 +25,7 @@ func InitDBEngine(ctx context.Context) (err error) {
 		default:
 		}
 		log.Info("ORM engine initialization attempt #%d/%d...", i+1, setting.Database.DBConnectRetries)
-		if err = models.NewEngine(ctx, migrations.Migrate); err == nil {
+		if err = db.NewEngine(ctx, migrations.Migrate); err == nil {
 			break
 		} else if i == setting.Database.DBConnectRetries-1 {
 			return err
@@ -34,6 +34,6 @@ func InitDBEngine(ctx context.Context) (err error) {
 		log.Info("Backing off for %d seconds", int64(setting.Database.DBConnectBackoff/time.Second))
 		time.Sleep(setting.Database.DBConnectBackoff)
 	}
-	models.HasEngine = true
+	db.HasEngine = true
 	return nil
 }
diff --git a/routers/install/install.go b/routers/install/install.go
index ad985cf18..8143ad808 100644
--- a/routers/install/install.go
+++ b/routers/install/install.go
@@ -15,6 +15,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/generate"
@@ -207,7 +208,7 @@ func SubmitInstall(ctx *context.Context) {
 	}
 
 	// Set test engine.
-	if err = models.NewTestEngine(); err != nil {
+	if err = db.NewTestEngine(); err != nil {
 		if strings.Contains(err.Error(), `Unknown database type: sqlite3`) {
 			ctx.Data["Err_DbType"] = true
 			ctx.RenderWithErr(ctx.Tr("install.sqlite3_not_available", "https://docs.gitea.io/en-us/install-from-binary/"), tplInstall, &form)
diff --git a/routers/web/admin/main_test.go b/routers/web/admin/main_test.go
index 352907c73..cfdefdb1b 100644
--- a/routers/web/admin/main_test.go
+++ b/routers/web/admin/main_test.go
@@ -8,9 +8,9 @@ import (
 	"path/filepath"
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", "..", ".."))
+	db.MainTest(m, filepath.Join("..", "..", ".."))
 }
diff --git a/routers/web/admin/users_test.go b/routers/web/admin/users_test.go
index 3d0b11a77..022d8f662 100644
--- a/routers/web/admin/users_test.go
+++ b/routers/web/admin/users_test.go
@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/test"
@@ -19,10 +20,10 @@ import (
 
 func TestNewUserPost_MustChangePassword(t *testing.T) {
 
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "admin/users/new")
 
-	u := models.AssertExistsAndLoadBean(t, &models.User{
+	u := db.AssertExistsAndLoadBean(t, &models.User{
 		IsAdmin: true,
 		ID:      2,
 	}).(*models.User)
@@ -56,10 +57,10 @@ func TestNewUserPost_MustChangePassword(t *testing.T) {
 }
 
 func TestNewUserPost_MustChangePasswordFalse(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "admin/users/new")
 
-	u := models.AssertExistsAndLoadBean(t, &models.User{
+	u := db.AssertExistsAndLoadBean(t, &models.User{
 		IsAdmin: true,
 		ID:      2,
 	}).(*models.User)
@@ -93,10 +94,10 @@ func TestNewUserPost_MustChangePasswordFalse(t *testing.T) {
 }
 
 func TestNewUserPost_InvalidEmail(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "admin/users/new")
 
-	u := models.AssertExistsAndLoadBean(t, &models.User{
+	u := db.AssertExistsAndLoadBean(t, &models.User{
 		IsAdmin: true,
 		ID:      2,
 	}).(*models.User)
@@ -123,10 +124,10 @@ func TestNewUserPost_InvalidEmail(t *testing.T) {
 }
 
 func TestNewUserPost_VisibilityDefaultPublic(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "admin/users/new")
 
-	u := models.AssertExistsAndLoadBean(t, &models.User{
+	u := db.AssertExistsAndLoadBean(t, &models.User{
 		IsAdmin: true,
 		ID:      2,
 	}).(*models.User)
@@ -161,10 +162,10 @@ func TestNewUserPost_VisibilityDefaultPublic(t *testing.T) {
 }
 
 func TestNewUserPost_VisibilityPrivate(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "admin/users/new")
 
-	u := models.AssertExistsAndLoadBean(t, &models.User{
+	u := db.AssertExistsAndLoadBean(t, &models.User{
 		IsAdmin: true,
 		ID:      2,
 	}).(*models.User)
diff --git a/routers/web/org/org_labels.go b/routers/web/org/org_labels.go
index 97a5437c6..17509c50f 100644
--- a/routers/web/org/org_labels.go
+++ b/routers/web/org/org_labels.go
@@ -8,6 +8,7 @@ import (
 	"net/http"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/web"
 	"code.gitea.io/gitea/services/forms"
@@ -98,7 +99,7 @@ func InitializeLabels(ctx *context.Context) {
 		return
 	}
 
-	if err := models.InitializeLabels(models.DefaultDBContext(), ctx.Org.Organization.ID, form.TemplateName, true); err != nil {
+	if err := models.InitializeLabels(db.DefaultContext(), ctx.Org.Organization.ID, form.TemplateName, true); err != nil {
 		if models.IsErrIssueLabelTemplateLoad(err) {
 			originalErr := err.(models.ErrIssueLabelTemplateLoad).OriginalError
 			ctx.Flash.Error(ctx.Tr("repo.issues.label_templates.fail_to_load_file", form.TemplateName, originalErr))
diff --git a/routers/web/repo/editor_test.go b/routers/web/repo/editor_test.go
index ec7aee1e7..8ab1fe1ee 100644
--- a/routers/web/repo/editor_test.go
+++ b/routers/web/repo/editor_test.go
@@ -7,7 +7,7 @@ package repo
 import (
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/test"
 
@@ -15,7 +15,7 @@ import (
 )
 
 func TestCleanUploadName(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 
 	var kases = map[string]string{
 		".git/refs/master":               "",
@@ -41,7 +41,7 @@ func TestCleanUploadName(t *testing.T) {
 }
 
 func TestGetUniquePatchBranchName(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1")
 	ctx.SetParams(":id", "1")
 	test.LoadRepo(t, ctx, 1)
@@ -56,7 +56,7 @@ func TestGetUniquePatchBranchName(t *testing.T) {
 }
 
 func TestGetClosestParentWithFiles(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1")
 	ctx.SetParams(":id", "1")
 	test.LoadRepo(t, ctx, 1)
diff --git a/routers/web/repo/issue_label.go b/routers/web/repo/issue_label.go
index abb529649..daed302dc 100644
--- a/routers/web/repo/issue_label.go
+++ b/routers/web/repo/issue_label.go
@@ -8,6 +8,7 @@ import (
 	"net/http"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/log"
@@ -38,7 +39,7 @@ func InitializeLabels(ctx *context.Context) {
 		return
 	}
 
-	if err := models.InitializeLabels(models.DefaultDBContext(), ctx.Repo.Repository.ID, form.TemplateName, false); err != nil {
+	if err := models.InitializeLabels(db.DefaultContext(), ctx.Repo.Repository.ID, form.TemplateName, false); err != nil {
 		if models.IsErrIssueLabelTemplateLoad(err) {
 			originalErr := err.(models.ErrIssueLabelTemplateLoad).OriginalError
 			ctx.Flash.Error(ctx.Tr("repo.issues.label_templates.fail_to_load_file", form.TemplateName, originalErr))
diff --git a/routers/web/repo/issue_label_test.go b/routers/web/repo/issue_label_test.go
index bf9e72a6f..8c3caabe1 100644
--- a/routers/web/repo/issue_label_test.go
+++ b/routers/web/repo/issue_label_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/test"
 	"code.gitea.io/gitea/modules/web"
 	"code.gitea.io/gitea/services/forms"
@@ -29,14 +30,14 @@ func int64SliceToCommaSeparated(a []int64) string {
 }
 
 func TestInitializeLabels(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1/labels/initialize")
 	test.LoadUser(t, ctx, 2)
 	test.LoadRepo(t, ctx, 2)
 	web.SetForm(ctx, &forms.InitializeLabelsForm{TemplateName: "Default"})
 	InitializeLabels(ctx)
 	assert.EqualValues(t, http.StatusFound, ctx.Resp.Status())
-	models.AssertExistsAndLoadBean(t, &models.Label{
+	db.AssertExistsAndLoadBean(t, &models.Label{
 		RepoID: 2,
 		Name:   "enhancement",
 		Color:  "#84b6eb",
@@ -45,7 +46,7 @@ func TestInitializeLabels(t *testing.T) {
 }
 
 func TestRetrieveLabels(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	for _, testCase := range []struct {
 		RepoID           int64
 		Sort             string
@@ -72,7 +73,7 @@ func TestRetrieveLabels(t *testing.T) {
 }
 
 func TestNewLabel(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1/labels/edit")
 	test.LoadUser(t, ctx, 2)
 	test.LoadRepo(t, ctx, 1)
@@ -82,7 +83,7 @@ func TestNewLabel(t *testing.T) {
 	})
 	NewLabel(ctx)
 	assert.EqualValues(t, http.StatusFound, ctx.Resp.Status())
-	models.AssertExistsAndLoadBean(t, &models.Label{
+	db.AssertExistsAndLoadBean(t, &models.Label{
 		Name:  "newlabel",
 		Color: "#abcdef",
 	})
@@ -90,7 +91,7 @@ func TestNewLabel(t *testing.T) {
 }
 
 func TestUpdateLabel(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1/labels/edit")
 	test.LoadUser(t, ctx, 2)
 	test.LoadRepo(t, ctx, 1)
@@ -101,7 +102,7 @@ func TestUpdateLabel(t *testing.T) {
 	})
 	UpdateLabel(ctx)
 	assert.EqualValues(t, http.StatusFound, ctx.Resp.Status())
-	models.AssertExistsAndLoadBean(t, &models.Label{
+	db.AssertExistsAndLoadBean(t, &models.Label{
 		ID:    2,
 		Name:  "newnameforlabel",
 		Color: "#abcdef",
@@ -110,20 +111,20 @@ func TestUpdateLabel(t *testing.T) {
 }
 
 func TestDeleteLabel(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1/labels/delete")
 	test.LoadUser(t, ctx, 2)
 	test.LoadRepo(t, ctx, 1)
 	ctx.Req.Form.Set("id", "2")
 	DeleteLabel(ctx)
 	assert.EqualValues(t, http.StatusOK, ctx.Resp.Status())
-	models.AssertNotExistsBean(t, &models.Label{ID: 2})
-	models.AssertNotExistsBean(t, &models.IssueLabel{LabelID: 2})
+	db.AssertNotExistsBean(t, &models.Label{ID: 2})
+	db.AssertNotExistsBean(t, &models.IssueLabel{LabelID: 2})
 	assert.Equal(t, ctx.Tr("repo.issues.label_deletion_success"), ctx.Flash.SuccessMsg)
 }
 
 func TestUpdateIssueLabel_Clear(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1/issues/labels")
 	test.LoadUser(t, ctx, 2)
 	test.LoadRepo(t, ctx, 1)
@@ -131,8 +132,8 @@ func TestUpdateIssueLabel_Clear(t *testing.T) {
 	ctx.Req.Form.Set("action", "clear")
 	UpdateIssueLabel(ctx)
 	assert.EqualValues(t, http.StatusOK, ctx.Resp.Status())
-	models.AssertNotExistsBean(t, &models.IssueLabel{IssueID: 1})
-	models.AssertNotExistsBean(t, &models.IssueLabel{IssueID: 3})
+	db.AssertNotExistsBean(t, &models.IssueLabel{IssueID: 1})
+	db.AssertNotExistsBean(t, &models.IssueLabel{IssueID: 3})
 	models.CheckConsistencyFor(t, &models.Label{})
 }
 
@@ -148,7 +149,7 @@ func TestUpdateIssueLabel_Toggle(t *testing.T) {
 		{"toggle", []int64{1, 3}, 1, false},
 		{"toggle", []int64{1, 2}, 2, true},
 	} {
-		models.PrepareTestEnv(t)
+		db.PrepareTestEnv(t)
 		ctx := test.MockContext(t, "user2/repo1/issues/labels")
 		test.LoadUser(t, ctx, 2)
 		test.LoadRepo(t, ctx, 1)
@@ -158,7 +159,7 @@ func TestUpdateIssueLabel_Toggle(t *testing.T) {
 		UpdateIssueLabel(ctx)
 		assert.EqualValues(t, http.StatusOK, ctx.Resp.Status())
 		for _, issueID := range testCase.IssueIDs {
-			models.AssertExistsIf(t, testCase.ExpectedAdd, &models.IssueLabel{
+			db.AssertExistsIf(t, testCase.ExpectedAdd, &models.IssueLabel{
 				IssueID: issueID,
 				LabelID: testCase.LabelID,
 			})
diff --git a/routers/web/repo/main_test.go b/routers/web/repo/main_test.go
index 47f266365..832256724 100644
--- a/routers/web/repo/main_test.go
+++ b/routers/web/repo/main_test.go
@@ -8,9 +8,9 @@ import (
 	"path/filepath"
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", "..", ".."))
+	db.MainTest(m, filepath.Join("..", "..", ".."))
 }
diff --git a/routers/web/repo/projects_test.go b/routers/web/repo/projects_test.go
index c43cf6d95..d3b78cc77 100644
--- a/routers/web/repo/projects_test.go
+++ b/routers/web/repo/projects_test.go
@@ -7,14 +7,14 @@ package repo
 import (
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/test"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestCheckProjectBoardChangePermissions(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1/projects/1/2")
 	test.LoadUser(t, ctx, 2)
 	test.LoadRepo(t, ctx, 1)
diff --git a/routers/web/repo/release_test.go b/routers/web/repo/release_test.go
index 004a6ef54..7ac49c012 100644
--- a/routers/web/repo/release_test.go
+++ b/routers/web/repo/release_test.go
@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/test"
 	"code.gitea.io/gitea/modules/web"
 	"code.gitea.io/gitea/services/forms"
@@ -43,7 +44,7 @@ func TestNewReleasePost(t *testing.T) {
 			},
 		},
 	} {
-		models.PrepareTestEnv(t)
+		db.PrepareTestEnv(t)
 
 		ctx := test.MockContext(t, "user2/repo1/releases/new")
 		test.LoadUser(t, ctx, 2)
@@ -51,14 +52,14 @@ func TestNewReleasePost(t *testing.T) {
 		test.LoadGitRepo(t, ctx)
 		web.SetForm(ctx, &testCase.Form)
 		NewReleasePost(ctx)
-		models.AssertExistsAndLoadBean(t, &models.Release{
+		db.AssertExistsAndLoadBean(t, &models.Release{
 			RepoID:      1,
 			PublisherID: 2,
 			TagName:     testCase.Form.TagName,
 			Target:      testCase.Form.Target,
 			Title:       testCase.Form.Title,
 			Note:        testCase.Form.Content,
-		}, models.Cond("is_draft=?", len(testCase.Form.Draft) > 0))
+		}, db.Cond("is_draft=?", len(testCase.Form.Draft) > 0))
 		ctx.Repo.GitRepo.Close()
 	}
 }
diff --git a/routers/web/repo/repo.go b/routers/web/repo/repo.go
index 98f60c6b5..46a80524e 100644
--- a/routers/web/repo/repo.go
+++ b/routers/web/repo/repo.go
@@ -13,6 +13,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/graceful"
@@ -342,7 +343,7 @@ func RedirectDownload(ctx *context.Context) {
 	)
 	tagNames := []string{vTag}
 	curRepo := ctx.Repo.Repository
-	releases, err := models.GetReleasesByRepoIDAndNames(models.DefaultDBContext(), curRepo.ID, tagNames)
+	releases, err := models.GetReleasesByRepoIDAndNames(db.DefaultContext(), curRepo.ID, tagNames)
 	if err != nil {
 		if models.IsErrAttachmentNotExist(err) {
 			ctx.Error(http.StatusNotFound)
@@ -379,7 +380,7 @@ func Download(ctx *context.Context) {
 		return
 	}
 
-	archiver, err := models.GetRepoArchiver(models.DefaultDBContext(), aReq.RepoID, aReq.Type, aReq.CommitID)
+	archiver, err := models.GetRepoArchiver(db.DefaultContext(), aReq.RepoID, aReq.Type, aReq.CommitID)
 	if err != nil {
 		ctx.ServerError("models.GetRepoArchiver", err)
 		return
@@ -409,7 +410,7 @@ func Download(ctx *context.Context) {
 				return
 			}
 			times++
-			archiver, err = models.GetRepoArchiver(models.DefaultDBContext(), aReq.RepoID, aReq.Type, aReq.CommitID)
+			archiver, err = models.GetRepoArchiver(db.DefaultContext(), aReq.RepoID, aReq.Type, aReq.CommitID)
 			if err != nil {
 				ctx.ServerError("archiver_service.StartArchive", err)
 				return
@@ -465,7 +466,7 @@ func InitiateDownload(ctx *context.Context) {
 		return
 	}
 
-	archiver, err := models.GetRepoArchiver(models.DefaultDBContext(), aReq.RepoID, aReq.Type, aReq.CommitID)
+	archiver, err := models.GetRepoArchiver(db.DefaultContext(), aReq.RepoID, aReq.Type, aReq.CommitID)
 	if err != nil {
 		ctx.ServerError("archiver_service.StartArchive", err)
 		return
diff --git a/routers/web/repo/settings_test.go b/routers/web/repo/settings_test.go
index 5190f12d5..f9986e44e 100644
--- a/routers/web/repo/settings_test.go
+++ b/routers/web/repo/settings_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/test"
@@ -42,7 +43,7 @@ func TestAddReadOnlyDeployKey(t *testing.T) {
 	} else {
 		return
 	}
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 
 	ctx := test.MockContext(t, "user2/repo1/settings/keys")
 
@@ -57,7 +58,7 @@ func TestAddReadOnlyDeployKey(t *testing.T) {
 	DeployKeysPost(ctx)
 	assert.EqualValues(t, http.StatusFound, ctx.Resp.Status())
 
-	models.AssertExistsAndLoadBean(t, &models.DeployKey{
+	db.AssertExistsAndLoadBean(t, &models.DeployKey{
 		Name:    addKeyForm.Title,
 		Content: addKeyForm.Content,
 		Mode:    models.AccessModeRead,
@@ -71,7 +72,7 @@ func TestAddReadWriteOnlyDeployKey(t *testing.T) {
 		return
 	}
 
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 
 	ctx := test.MockContext(t, "user2/repo1/settings/keys")
 
@@ -87,7 +88,7 @@ func TestAddReadWriteOnlyDeployKey(t *testing.T) {
 	DeployKeysPost(ctx)
 	assert.EqualValues(t, http.StatusFound, ctx.Resp.Status())
 
-	models.AssertExistsAndLoadBean(t, &models.DeployKey{
+	db.AssertExistsAndLoadBean(t, &models.DeployKey{
 		Name:    addKeyForm.Title,
 		Content: addKeyForm.Content,
 		Mode:    models.AccessModeWrite,
@@ -96,7 +97,7 @@ func TestAddReadWriteOnlyDeployKey(t *testing.T) {
 
 func TestCollaborationPost(t *testing.T) {
 
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1/issues/labels")
 	test.LoadUser(t, ctx, 2)
 	test.LoadUser(t, ctx, 4)
@@ -132,7 +133,7 @@ func TestCollaborationPost(t *testing.T) {
 
 func TestCollaborationPost_InactiveUser(t *testing.T) {
 
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1/issues/labels")
 	test.LoadUser(t, ctx, 2)
 	test.LoadUser(t, ctx, 9)
@@ -156,7 +157,7 @@ func TestCollaborationPost_InactiveUser(t *testing.T) {
 
 func TestCollaborationPost_AddCollaboratorTwice(t *testing.T) {
 
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1/issues/labels")
 	test.LoadUser(t, ctx, 2)
 	test.LoadUser(t, ctx, 4)
@@ -198,7 +199,7 @@ func TestCollaborationPost_AddCollaboratorTwice(t *testing.T) {
 
 func TestCollaborationPost_NonExistentUser(t *testing.T) {
 
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "user2/repo1/issues/labels")
 	test.LoadUser(t, ctx, 2)
 	test.LoadRepo(t, ctx, 1)
@@ -220,7 +221,7 @@ func TestCollaborationPost_NonExistentUser(t *testing.T) {
 }
 
 func TestAddTeamPost(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "org26/repo43")
 
 	ctx.Req.Form.Set("team", "team11")
@@ -260,7 +261,7 @@ func TestAddTeamPost(t *testing.T) {
 }
 
 func TestAddTeamPost_NotAllowed(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "org26/repo43")
 
 	ctx.Req.Form.Set("team", "team11")
@@ -301,7 +302,7 @@ func TestAddTeamPost_NotAllowed(t *testing.T) {
 }
 
 func TestAddTeamPost_AddTeamTwice(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "org26/repo43")
 
 	ctx.Req.Form.Set("team", "team11")
@@ -342,7 +343,7 @@ func TestAddTeamPost_AddTeamTwice(t *testing.T) {
 }
 
 func TestAddTeamPost_NonExistentTeam(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "org26/repo43")
 
 	ctx.Req.Form.Set("team", "team-non-existent")
@@ -375,7 +376,7 @@ func TestAddTeamPost_NonExistentTeam(t *testing.T) {
 }
 
 func TestDeleteTeam(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	ctx := test.MockContext(t, "org3/team1/repo3")
 
 	ctx.Req.Form.Set("id", "2")
diff --git a/routers/web/repo/wiki_test.go b/routers/web/repo/wiki_test.go
index bcdb8023a..df565487f 100644
--- a/routers/web/repo/wiki_test.go
+++ b/routers/web/repo/wiki_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/test"
 	"code.gitea.io/gitea/modules/web"
@@ -73,7 +74,7 @@ func assertPagesMetas(t *testing.T, expectedNames []string, metas interface{}) {
 }
 
 func TestWiki(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 
 	ctx := test.MockContext(t, "user2/repo1/wiki/_pages")
 	ctx.SetParams(":page", "Home")
@@ -85,7 +86,7 @@ func TestWiki(t *testing.T) {
 }
 
 func TestWikiPages(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 
 	ctx := test.MockContext(t, "user2/repo1/wiki/_pages")
 	test.LoadRepo(t, ctx, 1)
@@ -95,7 +96,7 @@ func TestWikiPages(t *testing.T) {
 }
 
 func TestNewWiki(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 
 	ctx := test.MockContext(t, "user2/repo1/wiki/_new")
 	test.LoadUser(t, ctx, 2)
@@ -110,7 +111,7 @@ func TestNewWikiPost(t *testing.T) {
 		"New page",
 		"&&&&",
 	} {
-		models.PrepareTestEnv(t)
+		db.PrepareTestEnv(t)
 
 		ctx := test.MockContext(t, "user2/repo1/wiki/_new")
 		test.LoadUser(t, ctx, 2)
@@ -128,7 +129,7 @@ func TestNewWikiPost(t *testing.T) {
 }
 
 func TestNewWikiPost_ReservedName(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 
 	ctx := test.MockContext(t, "user2/repo1/wiki/_new")
 	test.LoadUser(t, ctx, 2)
@@ -145,7 +146,7 @@ func TestNewWikiPost_ReservedName(t *testing.T) {
 }
 
 func TestEditWiki(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 
 	ctx := test.MockContext(t, "user2/repo1/wiki/_edit/Home")
 	ctx.SetParams(":page", "Home")
@@ -162,7 +163,7 @@ func TestEditWikiPost(t *testing.T) {
 		"Home",
 		"New/<page>",
 	} {
-		models.PrepareTestEnv(t)
+		db.PrepareTestEnv(t)
 		ctx := test.MockContext(t, "user2/repo1/wiki/_new/Home")
 		ctx.SetParams(":page", "Home")
 		test.LoadUser(t, ctx, 2)
@@ -183,7 +184,7 @@ func TestEditWikiPost(t *testing.T) {
 }
 
 func TestDeleteWikiPagePost(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 
 	ctx := test.MockContext(t, "user2/repo1/wiki/Home/delete")
 	test.LoadUser(t, ctx, 2)
@@ -202,7 +203,7 @@ func TestWikiRaw(t *testing.T) {
 		"Page With Spaced Name.md": "text/plain; charset=utf-8",
 		"Page-With-Spaced-Name.md": "text/plain; charset=utf-8",
 	} {
-		models.PrepareTestEnv(t)
+		db.PrepareTestEnv(t)
 
 		ctx := test.MockContext(t, "user2/repo1/wiki/raw/"+filepath)
 		ctx.SetParams("*", filepath)
diff --git a/routers/web/user/auth.go b/routers/web/user/auth.go
index a5c0a14d1..b4c52675f 100644
--- a/routers/web/user/auth.go
+++ b/routers/web/user/auth.go
@@ -14,6 +14,7 @@ import (
 	"strings"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/eventsource"
@@ -55,7 +56,7 @@ const (
 
 // AutoSignIn reads cookie and try to auto-login.
 func AutoSignIn(ctx *context.Context) (bool, error) {
-	if !models.HasEngine {
+	if !db.HasEngine {
 		return false, nil
 	}
 
diff --git a/routers/web/user/home_test.go b/routers/web/user/home_test.go
index b0109c354..daf473b27 100644
--- a/routers/web/user/home_test.go
+++ b/routers/web/user/home_test.go
@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/test"
 
@@ -18,7 +19,7 @@ import (
 func TestArchivedIssues(t *testing.T) {
 	// Arrange
 	setting.UI.IssuePagingNum = 1
-	assert.NoError(t, models.LoadFixtures())
+	assert.NoError(t, db.LoadFixtures())
 
 	ctx := test.MockContext(t, "issues")
 	test.LoadUser(t, ctx, 30)
@@ -51,7 +52,7 @@ func TestArchivedIssues(t *testing.T) {
 
 func TestIssues(t *testing.T) {
 	setting.UI.IssuePagingNum = 1
-	assert.NoError(t, models.LoadFixtures())
+	assert.NoError(t, db.LoadFixtures())
 
 	ctx := test.MockContext(t, "issues")
 	test.LoadUser(t, ctx, 2)
@@ -67,7 +68,7 @@ func TestIssues(t *testing.T) {
 
 func TestPulls(t *testing.T) {
 	setting.UI.IssuePagingNum = 20
-	assert.NoError(t, models.LoadFixtures())
+	assert.NoError(t, db.LoadFixtures())
 
 	ctx := test.MockContext(t, "pulls")
 	test.LoadUser(t, ctx, 2)
@@ -80,7 +81,7 @@ func TestPulls(t *testing.T) {
 
 func TestMilestones(t *testing.T) {
 	setting.UI.IssuePagingNum = 1
-	assert.NoError(t, models.LoadFixtures())
+	assert.NoError(t, db.LoadFixtures())
 
 	ctx := test.MockContext(t, "milestones")
 	test.LoadUser(t, ctx, 2)
@@ -99,7 +100,7 @@ func TestMilestones(t *testing.T) {
 
 func TestMilestonesForSpecificRepo(t *testing.T) {
 	setting.UI.IssuePagingNum = 1
-	assert.NoError(t, models.LoadFixtures())
+	assert.NoError(t, db.LoadFixtures())
 
 	ctx := test.MockContext(t, "milestones")
 	test.LoadUser(t, ctx, 2)
diff --git a/routers/web/user/main_test.go b/routers/web/user/main_test.go
index be17dd1f3..272e4b8b2 100644
--- a/routers/web/user/main_test.go
+++ b/routers/web/user/main_test.go
@@ -8,9 +8,9 @@ import (
 	"path/filepath"
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", "..", ".."))
+	db.MainTest(m, filepath.Join("..", "..", ".."))
 }
diff --git a/routers/web/user/oauth_test.go b/routers/web/user/oauth_test.go
index 40116d3c1..09abf1ee2 100644
--- a/routers/web/user/oauth_test.go
+++ b/routers/web/user/oauth_test.go
@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/services/auth/source/oauth2"
 
 	"github.com/golang-jwt/jwt"
@@ -39,7 +40,7 @@ func createAndParseToken(t *testing.T, grant *models.OAuth2Grant) *oauth2.OIDCTo
 }
 
 func TestNewAccessTokenResponse_OIDCToken(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	grants, err := models.GetOAuth2GrantsByUserID(3)
 	assert.NoError(t, err)
@@ -56,7 +57,7 @@ func TestNewAccessTokenResponse_OIDCToken(t *testing.T) {
 	assert.Empty(t, oidcToken.Email)
 	assert.False(t, oidcToken.EmailVerified)
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 5}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 5}).(*models.User)
 	grants, err = models.GetOAuth2GrantsByUserID(user.ID)
 	assert.NoError(t, err)
 	assert.Len(t, grants, 1)
diff --git a/routers/web/user/setting/account_test.go b/routers/web/user/setting/account_test.go
index 25b68da76..bfb7ac487 100644
--- a/routers/web/user/setting/account_test.go
+++ b/routers/web/user/setting/account_test.go
@@ -8,7 +8,7 @@ import (
 	"net/http"
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/test"
 	"code.gitea.io/gitea/modules/web"
@@ -81,7 +81,7 @@ func TestChangePassword(t *testing.T) {
 			PasswordComplexity: pcLU,
 		},
 	} {
-		models.PrepareTestEnv(t)
+		db.PrepareTestEnv(t)
 		ctx := test.MockContext(t, "user/settings/security")
 		test.LoadUser(t, ctx, 2)
 		test.LoadRepo(t, ctx, 1)
diff --git a/routers/web/user/setting/main_test.go b/routers/web/user/setting/main_test.go
index daa3f7fe5..a0fbe55ee 100644
--- a/routers/web/user/setting/main_test.go
+++ b/routers/web/user/setting/main_test.go
@@ -8,9 +8,9 @@ import (
 	"path/filepath"
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", "..", "..", ".."))
+	db.MainTest(m, filepath.Join("..", "..", "..", ".."))
 }
diff --git a/services/archiver/archiver.go b/services/archiver/archiver.go
index 7ae0a94d7..6d4d46e4e 100644
--- a/services/archiver/archiver.go
+++ b/services/archiver/archiver.go
@@ -14,6 +14,7 @@ import (
 	"strings"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/graceful"
 	"code.gitea.io/gitea/modules/log"
@@ -97,11 +98,11 @@ func (aReq *ArchiveRequest) GetArchiveName() string {
 }
 
 func doArchive(r *ArchiveRequest) (*models.RepoArchiver, error) {
-	ctx, commiter, err := models.TxDBContext()
+	ctx, committer, err := db.TxContext()
 	if err != nil {
 		return nil, err
 	}
-	defer commiter.Close()
+	defer committer.Close()
 
 	archiver, err := models.GetRepoArchiver(ctx, r.RepoID, r.Type, r.CommitID)
 	if err != nil {
@@ -206,7 +207,7 @@ func doArchive(r *ArchiveRequest) (*models.RepoArchiver, error) {
 		}
 	}
 
-	return archiver, commiter.Commit()
+	return archiver, committer.Commit()
 }
 
 // ArchiveRepository satisfies the ArchiveRequest being passed in.  Processing
diff --git a/services/archiver/archiver_test.go b/services/archiver/archiver_test.go
index 3f3f36998..94b0423d9 100644
--- a/services/archiver/archiver_test.go
+++ b/services/archiver/archiver_test.go
@@ -9,14 +9,14 @@ import (
 	"testing"
 	"time"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/test"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", ".."))
+	db.MainTest(m, filepath.Join("..", ".."))
 }
 
 func waitForCount(t *testing.T, num int) {
@@ -24,7 +24,7 @@ func waitForCount(t *testing.T, num int) {
 }
 
 func TestArchive_Basic(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	ctx := test.MockContext(t, "user27/repo49")
 	firstCommit, secondCommit := "51f84af23134", "aacbdfe9e1c4"
diff --git a/services/attachment/attachment.go b/services/attachment/attachment.go
index 4c356cd07..06f79be01 100644
--- a/services/attachment/attachment.go
+++ b/services/attachment/attachment.go
@@ -10,6 +10,7 @@ import (
 	"io"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/storage"
 	"code.gitea.io/gitea/modules/upload"
 
@@ -22,7 +23,7 @@ func NewAttachment(attach *models.Attachment, file io.Reader) (*models.Attachmen
 		return nil, fmt.Errorf("attachment %s should belong to a repository", attach.Name)
 	}
 
-	err := models.WithTx(func(ctx models.DBContext) error {
+	err := db.WithTx(func(ctx *db.Context) error {
 		attach.UUID = uuid.New().String()
 		size, err := storage.Attachments.Save(attach.RelativePath(), file, -1)
 		if err != nil {
@@ -30,7 +31,7 @@ func NewAttachment(attach *models.Attachment, file io.Reader) (*models.Attachmen
 		}
 		attach.Size = size
 
-		return models.Insert(ctx, attach)
+		return db.Insert(ctx, attach)
 	})
 
 	return attach, err
diff --git a/services/attachment/attachment_test.go b/services/attachment/attachment_test.go
index c11204b22..3e9e55a8f 100644
--- a/services/attachment/attachment_test.go
+++ b/services/attachment/attachment_test.go
@@ -10,18 +10,19 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", ".."))
+	db.MainTest(m, filepath.Join("..", ".."))
 }
 
 func TestUploadAttachment(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
 
 	fPath := "./attachment_test.go"
 	f, err := os.Open(fPath)
diff --git a/services/auth/group.go b/services/auth/group.go
index fb885b818..c396ae046 100644
--- a/services/auth/group.go
+++ b/services/auth/group.go
@@ -8,6 +8,7 @@ import (
 	"net/http"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 // Ensure the struct implements the interface.
@@ -60,7 +61,7 @@ func (b *Group) Free() error {
 
 // Verify extracts and validates
 func (b *Group) Verify(req *http.Request, w http.ResponseWriter, store DataStore, sess SessionStore) *models.User {
-	if !models.HasEngine {
+	if !db.HasEngine {
 		return nil
 	}
 
diff --git a/services/auth/oauth2.go b/services/auth/oauth2.go
index 665e5232c..e79b640ce 100644
--- a/services/auth/oauth2.go
+++ b/services/auth/oauth2.go
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/web/middleware"
@@ -109,7 +110,7 @@ func (o *OAuth2) userIDFromToken(req *http.Request, store DataStore) int64 {
 // If verification is successful returns an existing user object.
 // Returns nil if verification fails.
 func (o *OAuth2) Verify(req *http.Request, w http.ResponseWriter, store DataStore, sess SessionStore) *models.User {
-	if !models.HasEngine {
+	if !db.HasEngine {
 		return nil
 	}
 
diff --git a/services/auth/signin.go b/services/auth/signin.go
index 0ac2634c8..a7acb95ba 100644
--- a/services/auth/signin.go
+++ b/services/auth/signin.go
@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 
 	// Register the sources
@@ -25,7 +26,7 @@ func UserSignIn(username, password string) (*models.User, *models.LoginSource, e
 	if strings.Contains(username, "@") {
 		user = &models.User{Email: strings.ToLower(strings.TrimSpace(username))}
 		// check same email
-		cnt, err := models.Count(user)
+		cnt, err := db.Count(user)
 		if err != nil {
 			return nil, nil, err
 		}
diff --git a/services/auth/source/oauth2/init.go b/services/auth/source/oauth2/init.go
index 64328aa38..be31503ee 100644
--- a/services/auth/source/oauth2/init.go
+++ b/services/auth/source/oauth2/init.go
@@ -9,6 +9,7 @@ import (
 	"sync"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 
@@ -33,7 +34,7 @@ func Init() error {
 		return err
 	}
 
-	store, err := models.CreateStore(SessionTableName, UsersStoreKey)
+	store, err := db.CreateStore(SessionTableName, UsersStoreKey)
 	if err != nil {
 		return err
 	}
diff --git a/services/comments/comments.go b/services/comments/comments.go
index f8bdc8153..901b82e38 100644
--- a/services/comments/comments.go
+++ b/services/comments/comments.go
@@ -6,6 +6,7 @@ package comments
 
 import (
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/notification"
 )
 
@@ -22,7 +23,7 @@ func CreateIssueComment(doer *models.User, repo *models.Repository, issue *model
 	if err != nil {
 		return nil, err
 	}
-	mentions, err := issue.FindAndUpdateIssueMentions(models.DefaultDBContext(), doer, comment.Content)
+	mentions, err := issue.FindAndUpdateIssueMentions(db.DefaultContext(), doer, comment.Content)
 	if err != nil {
 		return nil, err
 	}
diff --git a/services/gitdiff/gitdiff.go b/services/gitdiff/gitdiff.go
index 65d0dab4c..239358789 100644
--- a/services/gitdiff/gitdiff.go
+++ b/services/gitdiff/gitdiff.go
@@ -23,6 +23,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/analyze"
 	"code.gitea.io/gitea/modules/charset"
 	"code.gitea.io/gitea/modules/git"
@@ -1122,7 +1123,7 @@ func parseHunks(curFile *DiffFile, maxLines, maxLineCharacters int, input *bufio
 			oid := strings.TrimPrefix(line[1:], lfs.MetaFileOidPrefix)
 			if len(oid) == 64 {
 				m := &models.LFSMetaObject{Pointer: lfs.Pointer{Oid: oid}}
-				count, err := models.Count(m)
+				count, err := db.Count(m)
 
 				if err == nil && count > 0 {
 					curFile.IsBin = true
diff --git a/services/gitdiff/gitdiff_test.go b/services/gitdiff/gitdiff_test.go
index 57364ace3..0d8d60d94 100644
--- a/services/gitdiff/gitdiff_test.go
+++ b/services/gitdiff/gitdiff_test.go
@@ -13,6 +13,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/highlight"
 	"code.gitea.io/gitea/modules/json"
@@ -492,10 +493,10 @@ func setupDefaultDiff() *Diff {
 	}
 }
 func TestDiff_LoadComments(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	issue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 2}).(*models.Issue)
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
+	issue := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 2}).(*models.Issue)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 1}).(*models.User)
 	diff := setupDefaultDiff()
 	assert.NoError(t, diff.LoadComments(issue, user))
 	assert.Len(t, diff.Files[0].Sections[0].Lines[0].Comments, 2)
diff --git a/services/gitdiff/main_test.go b/services/gitdiff/main_test.go
index 5ed3c75b7..1b83cbd68 100644
--- a/services/gitdiff/main_test.go
+++ b/services/gitdiff/main_test.go
@@ -8,9 +8,9 @@ import (
 	"path/filepath"
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", ".."))
+	db.MainTest(m, filepath.Join("..", ".."))
 }
diff --git a/services/issue/assignee_test.go b/services/issue/assignee_test.go
index 2d96368ec..5684ed6d8 100644
--- a/services/issue/assignee_test.go
+++ b/services/issue/assignee_test.go
@@ -8,11 +8,12 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestDeleteNotPassedAssignee(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	// Fake issue with assignees
 	issue, err := models.GetIssueWithAttrsByID(1)
diff --git a/services/issue/issue.go b/services/issue/issue.go
index 90f689a55..b2ac24e08 100644
--- a/services/issue/issue.go
+++ b/services/issue/issue.go
@@ -6,6 +6,7 @@ package issue
 
 import (
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/notification"
 	"code.gitea.io/gitea/modules/util"
@@ -23,7 +24,7 @@ func NewIssue(repo *models.Repository, issue *models.Issue, labelIDs []int64, uu
 		}
 	}
 
-	mentions, err := issue.FindAndUpdateIssueMentions(models.DefaultDBContext(), issue.Poster, issue.Content)
+	mentions, err := issue.FindAndUpdateIssueMentions(db.DefaultContext(), issue.Poster, issue.Content)
 	if err != nil {
 		return err
 	}
diff --git a/services/issue/label_test.go b/services/issue/label_test.go
index 065202894..8a3a77ecb 100644
--- a/services/issue/label_test.go
+++ b/services/issue/label_test.go
@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -23,16 +24,16 @@ func TestIssue_AddLabels(t *testing.T) {
 		{2, []int64{}, 1},     // pull-request, empty
 	}
 	for _, test := range tests {
-		assert.NoError(t, models.PrepareTestDatabase())
-		issue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: test.issueID}).(*models.Issue)
+		assert.NoError(t, db.PrepareTestDatabase())
+		issue := db.AssertExistsAndLoadBean(t, &models.Issue{ID: test.issueID}).(*models.Issue)
 		labels := make([]*models.Label, len(test.labelIDs))
 		for i, labelID := range test.labelIDs {
-			labels[i] = models.AssertExistsAndLoadBean(t, &models.Label{ID: labelID}).(*models.Label)
+			labels[i] = db.AssertExistsAndLoadBean(t, &models.Label{ID: labelID}).(*models.Label)
 		}
-		doer := models.AssertExistsAndLoadBean(t, &models.User{ID: test.doerID}).(*models.User)
+		doer := db.AssertExistsAndLoadBean(t, &models.User{ID: test.doerID}).(*models.User)
 		assert.NoError(t, AddLabels(issue, doer, labels))
 		for _, labelID := range test.labelIDs {
-			models.AssertExistsAndLoadBean(t, &models.IssueLabel{IssueID: test.issueID, LabelID: labelID})
+			db.AssertExistsAndLoadBean(t, &models.IssueLabel{IssueID: test.issueID, LabelID: labelID})
 		}
 	}
 }
@@ -49,11 +50,11 @@ func TestIssue_AddLabel(t *testing.T) {
 		{2, 1, 2}, // pull-request, already-added label
 	}
 	for _, test := range tests {
-		assert.NoError(t, models.PrepareTestDatabase())
-		issue := models.AssertExistsAndLoadBean(t, &models.Issue{ID: test.issueID}).(*models.Issue)
-		label := models.AssertExistsAndLoadBean(t, &models.Label{ID: test.labelID}).(*models.Label)
-		doer := models.AssertExistsAndLoadBean(t, &models.User{ID: test.doerID}).(*models.User)
+		assert.NoError(t, db.PrepareTestDatabase())
+		issue := db.AssertExistsAndLoadBean(t, &models.Issue{ID: test.issueID}).(*models.Issue)
+		label := db.AssertExistsAndLoadBean(t, &models.Label{ID: test.labelID}).(*models.Label)
+		doer := db.AssertExistsAndLoadBean(t, &models.User{ID: test.doerID}).(*models.User)
 		assert.NoError(t, AddLabel(issue, doer, label))
-		models.AssertExistsAndLoadBean(t, &models.IssueLabel{IssueID: test.issueID, LabelID: test.labelID})
+		db.AssertExistsAndLoadBean(t, &models.IssueLabel{IssueID: test.issueID, LabelID: test.labelID})
 	}
 }
diff --git a/services/issue/main_test.go b/services/issue/main_test.go
index b056678a4..134983794 100644
--- a/services/issue/main_test.go
+++ b/services/issue/main_test.go
@@ -8,9 +8,9 @@ import (
 	"path/filepath"
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", ".."))
+	db.MainTest(m, filepath.Join("..", ".."))
 }
diff --git a/services/mailer/mail_test.go b/services/mailer/mail_test.go
index 0a9112f3b..cbac7912b 100644
--- a/services/mailer/mail_test.go
+++ b/services/mailer/mail_test.go
@@ -11,6 +11,7 @@ import (
 	texttmpl "text/template"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/setting"
 
 	"github.com/stretchr/testify/assert"
@@ -40,7 +41,7 @@ const bodyTpl = `
 `
 
 func prepareMailerTest(t *testing.T) (doer *models.User, repo *models.Repository, issue *models.Issue, comment *models.Comment) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	var mailService = setting.Mailer{
 		From: "test@gitea.com",
 	}
@@ -48,11 +49,11 @@ func prepareMailerTest(t *testing.T) (doer *models.User, repo *models.Repository
 	setting.MailService = &mailService
 	setting.Domain = "localhost"
 
-	doer = models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	repo = models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1, Owner: doer}).(*models.Repository)
-	issue = models.AssertExistsAndLoadBean(t, &models.Issue{ID: 1, Repo: repo, Poster: doer}).(*models.Issue)
+	doer = db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo = db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1, Owner: doer}).(*models.Repository)
+	issue = db.AssertExistsAndLoadBean(t, &models.Issue{ID: 1, Repo: repo, Poster: doer}).(*models.Issue)
 	assert.NoError(t, issue.LoadRepo())
-	comment = models.AssertExistsAndLoadBean(t, &models.Comment{ID: 2, Issue: issue}).(*models.Comment)
+	comment = db.AssertExistsAndLoadBean(t, &models.Comment{ID: 2, Issue: issue}).(*models.Comment)
 	return
 }
 
@@ -139,8 +140,8 @@ func TestTemplateSelection(t *testing.T) {
 		Content: "test body", Comment: comment}, recipients, false, "TestTemplateSelection")
 	expect(t, msg, "issue/default/subject", "issue/default/body")
 
-	pull := models.AssertExistsAndLoadBean(t, &models.Issue{ID: 2, Repo: repo, Poster: doer}).(*models.Issue)
-	comment = models.AssertExistsAndLoadBean(t, &models.Comment{ID: 4, Issue: pull}).(*models.Comment)
+	pull := db.AssertExistsAndLoadBean(t, &models.Issue{ID: 2, Repo: repo, Poster: doer}).(*models.Issue)
+	comment = db.AssertExistsAndLoadBean(t, &models.Comment{ID: 4, Issue: pull}).(*models.Comment)
 	msg = testComposeIssueCommentMessage(t, &mailCommentContext{Issue: pull, Doer: doer, ActionType: models.ActionCommentPull,
 		Content: "test body", Comment: comment}, recipients, false, "TestTemplateSelection")
 	expect(t, msg, "pull/comment/subject", "pull/comment/body")
diff --git a/services/mailer/main_test.go b/services/mailer/main_test.go
index bbd121024..2fbe9c54a 100644
--- a/services/mailer/main_test.go
+++ b/services/mailer/main_test.go
@@ -8,9 +8,9 @@ import (
 	"path/filepath"
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", ".."))
+	db.MainTest(m, filepath.Join("..", ".."))
 }
diff --git a/services/mirror/mirror_pull.go b/services/mirror/mirror_pull.go
index 5bd08fa9b..1c0bf2b59 100644
--- a/services/mirror/mirror_pull.go
+++ b/services/mirror/mirror_pull.go
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/cache"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/lfs"
@@ -203,7 +204,7 @@ func runSync(ctx context.Context, m *models.Mirror) ([]*mirrorSyncResult, bool)
 	gitRepo.Close()
 
 	log.Trace("SyncMirrors [repo: %-v]: updating size of repository", m.Repo)
-	if err := m.Repo.UpdateSize(models.DefaultDBContext()); err != nil {
+	if err := m.Repo.UpdateSize(db.DefaultContext()); err != nil {
 		log.Error("Failed to update size for mirror repository: %v", err)
 	}
 
diff --git a/services/pull/check_test.go b/services/pull/check_test.go
index f6614ea0a..8beea3d56 100644
--- a/services/pull/check_test.go
+++ b/services/pull/check_test.go
@@ -11,13 +11,14 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/queue"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestPullRequest_AddToTaskQueue(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	idChan := make(chan int64, 10)
 
@@ -41,11 +42,11 @@ func TestPullRequest_AddToTaskQueue(t *testing.T) {
 
 	prQueue = q.(queue.UniqueQueue)
 
-	pr := models.AssertExistsAndLoadBean(t, &models.PullRequest{ID: 2}).(*models.PullRequest)
+	pr := db.AssertExistsAndLoadBean(t, &models.PullRequest{ID: 2}).(*models.PullRequest)
 	AddToTaskQueue(pr)
 
 	assert.Eventually(t, func() bool {
-		pr = models.AssertExistsAndLoadBean(t, &models.PullRequest{ID: 2}).(*models.PullRequest)
+		pr = db.AssertExistsAndLoadBean(t, &models.PullRequest{ID: 2}).(*models.PullRequest)
 		return pr.Status == models.PullRequestStatusChecking
 	}, 1*time.Second, 100*time.Millisecond)
 
@@ -70,7 +71,7 @@ func TestPullRequest_AddToTaskQueue(t *testing.T) {
 	assert.False(t, has)
 	assert.NoError(t, err)
 
-	pr = models.AssertExistsAndLoadBean(t, &models.PullRequest{ID: 2}).(*models.PullRequest)
+	pr = db.AssertExistsAndLoadBean(t, &models.PullRequest{ID: 2}).(*models.PullRequest)
 	assert.Equal(t, models.PullRequestStatusChecking, pr.Status)
 
 	for _, callback := range queueShutdown {
diff --git a/services/pull/main_test.go b/services/pull/main_test.go
index 6c49e8fbf..c8d3394e8 100644
--- a/services/pull/main_test.go
+++ b/services/pull/main_test.go
@@ -9,9 +9,9 @@ import (
 	"path/filepath"
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", ".."))
+	db.MainTest(m, filepath.Join("..", ".."))
 }
diff --git a/services/pull/pull.go b/services/pull/pull.go
index 23407ea67..d78d9b1bd 100644
--- a/services/pull/pull.go
+++ b/services/pull/pull.go
@@ -14,6 +14,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/graceful"
 	"code.gitea.io/gitea/modules/json"
@@ -58,7 +59,7 @@ func NewPullRequest(repo *models.Repository, pull *models.Issue, labelIDs []int6
 		return err
 	}
 
-	mentions, err := pull.FindAndUpdateIssueMentions(models.DefaultDBContext(), pull.Poster, pull.Content)
+	mentions, err := pull.FindAndUpdateIssueMentions(db.DefaultContext(), pull.Poster, pull.Content)
 	if err != nil {
 		return err
 	}
diff --git a/services/pull/review.go b/services/pull/review.go
index 3aa457062..ce34cc59d 100644
--- a/services/pull/review.go
+++ b/services/pull/review.go
@@ -12,6 +12,7 @@ import (
 	"strings"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/notification"
@@ -58,7 +59,7 @@ func CreateCodeComment(doer *models.User, gitRepo *git.Repository, issue *models
 			return nil, err
 		}
 
-		mentions, err := issue.FindAndUpdateIssueMentions(models.DefaultDBContext(), doer, comment.Content)
+		mentions, err := issue.FindAndUpdateIssueMentions(db.DefaultContext(), doer, comment.Content)
 		if err != nil {
 			return nil, err
 		}
@@ -245,7 +246,7 @@ func SubmitReview(doer *models.User, gitRepo *git.Repository, issue *models.Issu
 		return nil, nil, err
 	}
 
-	ctx := models.DefaultDBContext()
+	ctx := db.DefaultContext()
 	mentions, err := issue.FindAndUpdateIssueMentions(ctx, doer, comm.Content)
 	if err != nil {
 		return nil, nil, err
diff --git a/services/release/release.go b/services/release/release.go
index 4a55f73a3..a9181398b 100644
--- a/services/release/release.go
+++ b/services/release/release.go
@@ -10,6 +10,7 @@ import (
 	"strings"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/notification"
@@ -122,7 +123,7 @@ func CreateRelease(gitRepo *git.Repository, rel *models.Release, attachmentUUIDs
 		return err
 	}
 
-	if err = models.AddReleaseAttachments(models.DefaultDBContext(), rel.ID, attachmentUUIDs); err != nil {
+	if err = models.AddReleaseAttachments(db.DefaultContext(), rel.ID, attachmentUUIDs); err != nil {
 		return err
 	}
 
@@ -188,11 +189,11 @@ func UpdateRelease(doer *models.User, gitRepo *git.Repository, rel *models.Relea
 	}
 	rel.LowerTagName = strings.ToLower(rel.TagName)
 
-	ctx, commiter, err := models.TxDBContext()
+	ctx, committer, err := db.TxContext()
 	if err != nil {
 		return err
 	}
-	defer commiter.Close()
+	defer committer.Close()
 
 	if err = models.UpdateRelease(ctx, rel); err != nil {
 		return err
@@ -249,7 +250,7 @@ func UpdateRelease(doer *models.User, gitRepo *git.Repository, rel *models.Relea
 		}
 	}
 
-	if err = commiter.Commit(); err != nil {
+	if err = committer.Commit(); err != nil {
 		return
 	}
 
@@ -310,7 +311,7 @@ func DeleteReleaseByID(id int64, doer *models.User, delTag bool) error {
 	} else {
 		rel.IsTag = true
 
-		if err = models.UpdateRelease(models.DefaultDBContext(), rel); err != nil {
+		if err = models.UpdateRelease(db.DefaultContext(), rel); err != nil {
 			return fmt.Errorf("Update: %v", err)
 		}
 	}
diff --git a/services/release/release_test.go b/services/release/release_test.go
index 936f2ab71..e53e4c935 100644
--- a/services/release/release_test.go
+++ b/services/release/release_test.go
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/services/attachment"
 
@@ -18,14 +19,14 @@ import (
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", ".."))
+	db.MainTest(m, filepath.Join("..", ".."))
 }
 
 func TestRelease_Create(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 	repoPath := models.RepoPath(user.Name, repo.Name)
 
 	gitRepo, err := git.OpenRepository(repoPath)
@@ -126,10 +127,10 @@ func TestRelease_Create(t *testing.T) {
 }
 
 func TestRelease_Update(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 	repoPath := models.RepoPath(user.Name, repo.Name)
 
 	gitRepo, err := git.OpenRepository(repoPath)
@@ -268,10 +269,10 @@ func TestRelease_Update(t *testing.T) {
 }
 
 func TestRelease_createTag(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 	repoPath := models.RepoPath(user.Name, repo.Name)
 
 	gitRepo, err := git.OpenRepository(repoPath)
@@ -351,9 +352,9 @@ func TestRelease_createTag(t *testing.T) {
 }
 
 func TestCreateNewTag(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
-	user := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	assert.NoError(t, db.PrepareTestDatabase())
+	user := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 
 	assert.NoError(t, CreateNewTag(user, repo, "master", "v2.0",
 		"v2.0 is released \n\n BUGFIX: .... \n\n 123"))
diff --git a/services/repository/generate.go b/services/repository/generate.go
index 43cbb45a4..5a9f6aa65 100644
--- a/services/repository/generate.go
+++ b/services/repository/generate.go
@@ -6,6 +6,7 @@ package repository
 
 import (
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/notification"
 	repo_module "code.gitea.io/gitea/modules/repository"
@@ -20,7 +21,7 @@ func GenerateRepository(doer, owner *models.User, templateRepo *models.Repositor
 	}
 
 	var generateRepo *models.Repository
-	if err = models.WithTx(func(ctx models.DBContext) error {
+	if err = db.WithTx(func(ctx *db.Context) error {
 		generateRepo, err = repo_module.GenerateRepository(ctx, doer, owner, templateRepo, opts)
 		if err != nil {
 			return err
diff --git a/services/repository/main_test.go b/services/repository/main_test.go
index f13f35863..91d0d36ca 100644
--- a/services/repository/main_test.go
+++ b/services/repository/main_test.go
@@ -8,9 +8,9 @@ import (
 	"path/filepath"
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", ".."))
+	db.MainTest(m, filepath.Join("..", ".."))
 }
diff --git a/services/repository/push.go b/services/repository/push.go
index cf7060ade..f7590d578 100644
--- a/services/repository/push.go
+++ b/services/repository/push.go
@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/cache"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/graceful"
@@ -82,7 +83,7 @@ func pushUpdates(optsList []*repo_module.PushUpdateOptions) error {
 	}
 	defer gitRepo.Close()
 
-	if err = repo.UpdateSize(models.DefaultDBContext()); err != nil {
+	if err = repo.UpdateSize(db.DefaultContext()); err != nil {
 		log.Error("Failed to update size for repository: %v", err)
 	}
 
diff --git a/services/repository/transfer_test.go b/services/repository/transfer_test.go
index c92844674..40ccfdfb5 100644
--- a/services/repository/transfer_test.go
+++ b/services/repository/transfer_test.go
@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/notification"
 	"code.gitea.io/gitea/modules/notification/action"
 	"code.gitea.io/gitea/modules/util"
@@ -27,14 +28,14 @@ func registerNotifier() {
 func TestTransferOwnership(t *testing.T) {
 	registerNotifier()
 
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	doer := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)
-	repo.Owner = models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	doer := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)
+	repo.Owner = db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 	assert.NoError(t, TransferOwnership(doer, doer, repo, nil))
 
-	transferredRepo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)
+	transferredRepo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)
 	assert.EqualValues(t, 2, transferredRepo.OwnerID)
 
 	exist, err := util.IsExist(models.RepoPath("user3", "repo3"))
@@ -43,7 +44,7 @@ func TestTransferOwnership(t *testing.T) {
 	exist, err = util.IsExist(models.RepoPath("user2", "repo3"))
 	assert.NoError(t, err)
 	assert.True(t, exist)
-	models.AssertExistsAndLoadBean(t, &models.Action{
+	db.AssertExistsAndLoadBean(t, &models.Action{
 		OpType:    models.ActionTransferRepo,
 		ActUserID: 2,
 		RepoID:    3,
@@ -54,12 +55,12 @@ func TestTransferOwnership(t *testing.T) {
 }
 
 func TestStartRepositoryTransferSetPermission(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	doer := models.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)
-	recipient := models.AssertExistsAndLoadBean(t, &models.User{ID: 5}).(*models.User)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)
-	repo.Owner = models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+	doer := db.AssertExistsAndLoadBean(t, &models.User{ID: 3}).(*models.User)
+	recipient := db.AssertExistsAndLoadBean(t, &models.User{ID: 5}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 3}).(*models.Repository)
+	repo.Owner = db.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
 
 	hasAccess, err := models.HasAccess(recipient.ID, repo)
 	assert.NoError(t, err)
diff --git a/services/webhook/main_test.go b/services/webhook/main_test.go
index 6cb0cffe4..7aef4b3a5 100644
--- a/services/webhook/main_test.go
+++ b/services/webhook/main_test.go
@@ -8,9 +8,9 @@ import (
 	"path/filepath"
 	"testing"
 
-	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", ".."))
+	db.MainTest(m, filepath.Join("..", ".."))
 }
diff --git a/services/webhook/webhook_test.go b/services/webhook/webhook_test.go
index 10c32a948..095b30713 100644
--- a/services/webhook/webhook_test.go
+++ b/services/webhook/webhook_test.go
@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	api "code.gitea.io/gitea/modules/structs"
 	"github.com/stretchr/testify/assert"
 )
@@ -25,52 +26,52 @@ func TestWebhook_GetSlackHook(t *testing.T) {
 }
 
 func TestPrepareWebhooks(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 	hookTasks := []*models.HookTask{
 		{RepoID: repo.ID, HookID: 1, EventType: models.HookEventPush},
 	}
 	for _, hookTask := range hookTasks {
-		models.AssertNotExistsBean(t, hookTask)
+		db.AssertNotExistsBean(t, hookTask)
 	}
 	assert.NoError(t, PrepareWebhooks(repo, models.HookEventPush, &api.PushPayload{Commits: []*api.PayloadCommit{{}}}))
 	for _, hookTask := range hookTasks {
-		models.AssertExistsAndLoadBean(t, hookTask)
+		db.AssertExistsAndLoadBean(t, hookTask)
 	}
 }
 
 func TestPrepareWebhooksBranchFilterMatch(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 2}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 2}).(*models.Repository)
 	hookTasks := []*models.HookTask{
 		{RepoID: repo.ID, HookID: 4, EventType: models.HookEventPush},
 	}
 	for _, hookTask := range hookTasks {
-		models.AssertNotExistsBean(t, hookTask)
+		db.AssertNotExistsBean(t, hookTask)
 	}
 	// this test also ensures that * doesn't handle / in any special way (like shell would)
 	assert.NoError(t, PrepareWebhooks(repo, models.HookEventPush, &api.PushPayload{Ref: "refs/heads/feature/7791", Commits: []*api.PayloadCommit{{}}}))
 	for _, hookTask := range hookTasks {
-		models.AssertExistsAndLoadBean(t, hookTask)
+		db.AssertExistsAndLoadBean(t, hookTask)
 	}
 }
 
 func TestPrepareWebhooksBranchFilterNoMatch(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 2}).(*models.Repository)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 2}).(*models.Repository)
 	hookTasks := []*models.HookTask{
 		{RepoID: repo.ID, HookID: 4, EventType: models.HookEventPush},
 	}
 	for _, hookTask := range hookTasks {
-		models.AssertNotExistsBean(t, hookTask)
+		db.AssertNotExistsBean(t, hookTask)
 	}
 	assert.NoError(t, PrepareWebhooks(repo, models.HookEventPush, &api.PushPayload{Ref: "refs/heads/fix_weird_bug"}))
 
 	for _, hookTask := range hookTasks {
-		models.AssertNotExistsBean(t, hookTask)
+		db.AssertNotExistsBean(t, hookTask)
 	}
 }
 
diff --git a/services/wiki/wiki_test.go b/services/wiki/wiki_test.go
index 6c861d556..ff4dcf334 100644
--- a/services/wiki/wiki_test.go
+++ b/services/wiki/wiki_test.go
@@ -11,6 +11,7 @@ import (
 	"testing"
 
 	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/util"
 
@@ -18,7 +19,7 @@ import (
 )
 
 func TestMain(m *testing.M) {
-	models.MainTest(m, filepath.Join("..", ".."))
+	db.MainTest(m, filepath.Join("..", ".."))
 }
 
 func TestWikiNameToSubURL(t *testing.T) {
@@ -110,23 +111,23 @@ func TestWikiNameToFilenameToName(t *testing.T) {
 }
 
 func TestRepository_InitWiki(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 	// repo1 already has a wiki
-	repo1 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	repo1 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 	assert.NoError(t, InitWiki(repo1))
 
 	// repo2 does not already have a wiki
-	repo2 := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 2}).(*models.Repository)
+	repo2 := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 2}).(*models.Repository)
 	assert.NoError(t, InitWiki(repo2))
 	assert.True(t, repo2.HasWiki())
 }
 
 func TestRepository_AddWikiPage(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 	const wikiContent = "This is the wiki content"
 	const commitMsg = "Commit message"
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	doer := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	doer := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	for _, wikiName := range []string{
 		"Another page",
 		"Here's a <tag> and a/slash",
@@ -166,18 +167,18 @@ func TestRepository_AddWikiPage(t *testing.T) {
 }
 
 func TestRepository_EditWikiPage(t *testing.T) {
-	assert.NoError(t, models.PrepareTestDatabase())
+	assert.NoError(t, db.PrepareTestDatabase())
 
 	const newWikiContent = "This is the new content"
 	const commitMsg = "Commit message"
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	doer := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	doer := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	for _, newWikiName := range []string{
 		"Home", // same name as before
 		"New home",
 		"New/name/with/slashes",
 	} {
-		models.PrepareTestEnv(t)
+		db.PrepareTestEnv(t)
 		assert.NoError(t, EditWikiPage(doer, repo, "Home", newWikiName, newWikiContent, commitMsg))
 
 		// Now need to show that the page has been added:
@@ -199,9 +200,9 @@ func TestRepository_EditWikiPage(t *testing.T) {
 }
 
 func TestRepository_DeleteWikiPage(t *testing.T) {
-	models.PrepareTestEnv(t)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
-	doer := models.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
+	db.PrepareTestEnv(t)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	doer := db.AssertExistsAndLoadBean(t, &models.User{ID: 2}).(*models.User)
 	assert.NoError(t, DeleteWikiPage(doer, repo, "Home"))
 
 	// Now need to show that the page has been added:
@@ -216,8 +217,8 @@ func TestRepository_DeleteWikiPage(t *testing.T) {
 }
 
 func TestPrepareWikiFileName(t *testing.T) {
-	models.PrepareTestEnv(t)
-	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	db.PrepareTestEnv(t)
+	repo := db.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
 	gitRepo, err := git.OpenRepository(repo.WikiPath())
 	defer gitRepo.Close()
 	assert.NoError(t, err)
@@ -267,7 +268,7 @@ func TestPrepareWikiFileName(t *testing.T) {
 }
 
 func TestPrepareWikiFileName_FirstPage(t *testing.T) {
-	models.PrepareTestEnv(t)
+	db.PrepareTestEnv(t)
 
 	// Now create a temporaryDirectory
 	tmpDir, err := ioutil.TempDir("", "empty-wiki")